Closed monojk closed 3 years ago
UedaTakeyuki
commented
3 years ago Hi, monojk!
I'm slightly confused about how to connected mh_z19 with Raspberry Pi. So, would you please tell me more detail on how to connect the mh_z19 sensor and RPi? Is the mh_z19 sensor module connected with RPi directory by UART on RPi? Or connected by something USB-Serial converter?
If possible, could you please attach a photo of how to cabling? Thank you.
monojk
commented
3 years ago The connection is according to the cabling in your README.md
UedaTakeyuki
commented
3 years ago I'm now clear. The connection seems no problem.
The serial is /dev/serial1 -> ttyAMA0
Would you please attach here how was "ls -la /dev"? thank you for your kindly cooperation for the debugging!
nincube8
commented
3 years ago Make sure that you put RxD to TxD, and TxD to RxD on the Pi. Then you need to make sure your Pi has created the symbolic links in the system. Reboot, and check you MH-z19 for the Orange light. Make sure I2C is enabled as well.
On Sat, Aug 29, 2020 at 8:18 AM monojk notifications@github.com wrote:
The connection is according to the cabling in your README.md [image: 2020-08-29 16 12 20] https://user-images.githubusercontent.com/25121142/91638914-1b35a480-ea13-11ea-864a-d4e09e04b979.jpg
— You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub https://github.com/UedaTakeyuki/mh-z19/issues/22#issuecomment-683296932, or unsubscribe https://github.com/notifications/unsubscribe-auth/AEBLRRNY5D2HDRVOIU5N62LSDEE2TANCNFSM4QO7BF3Q .
monojk
commented
3 years ago I'm now clear. The connection seems no problem.
The serial is /dev/serial1 -> ttyAMA0
Would you please attach here how was "ls -la /dev"? thank you for your kindly cooperation for the debugging!
pi@rp3b:~ $ ls -la /dev insgesamt 4 drwxr-xr-x 16 root root 3680 Aug 29 16:11 . drwxr-xr-x 21 root root 4096 Apr 8 2019 .. crw-r--r-- 1 root root 10, 235 Aug 28 10:22 autofs drwxr-xr-x 2 root root 640 Aug 28 10:22 block crw------- 1 root root 10, 234 Aug 28 10:22 btrfs-control drwxr-xr-x 3 root root 60 Jan 1 1970 bus crw------- 1 root root 10, 63 Aug 28 10:22 cachefiles drwxr-xr-x 2 root root 2780 Aug 29 16:11 char crw------- 1 root root 5, 1 Aug 28 10:23 console crw------- 1 root root 10, 62 Aug 28 10:22 cpu_dma_latency crw------- 1 root root 10, 203 Aug 28 10:22 cuse drwxr-xr-x 7 root root 140 Aug 28 10:22 disk crw-rw---- 1 root video 29, 0 Aug 28 10:22 fb0 lrwxrwxrwx 1 root root 13 Nov 3 2016 fd -> /proc/self/fd crw-rw-rw- 1 root root 1, 7 Aug 28 10:22 full crw-rw-rw- 1 root root 10, 229 Aug 28 10:23 fuse crw-rw---- 1 root gpio 254, 0 Aug 28 10:22 gpiochip0 crw-rw---- 1 root gpio 254, 1 Aug 28 10:22 gpiochip1 crw-rw---- 1 root gpio 247, 0 Aug 28 10:22 gpiomem crw------- 1 root root 10, 183 Aug 28 10:22 hwrng lrwxrwxrwx 1 root root 25 Nov 3 2016 initctl -> /run/systemd/initctl/fifo drwxr-xr-x 2 root root 60 Jan 1 1970 input crw-r--r-- 1 root root 1, 11 Aug 28 10:22 kmsg lrwxrwxrwx 1 root root 28 Nov 3 2016 log -> /run/systemd/journal/dev-log brw-rw---- 1 root disk 7, 0 Aug 28 10:22 loop0 brw-rw---- 1 root disk 7, 1 Aug 28 10:22 loop1 brw-rw---- 1 root disk 7, 2 Aug 28 10:22 loop2 brw-rw---- 1 root disk 7, 3 Aug 28 10:22 loop3 brw-rw---- 1 root disk 7, 4 Aug 28 10:22 loop4 brw-rw---- 1 root disk 7, 5 Aug 28 10:22 loop5 brw-rw---- 1 root disk 7, 6 Aug 28 10:22 loop6 brw-rw---- 1 root disk 7, 7 Aug 28 10:22 loop7 crw-rw---- 1 root disk 10, 237 Aug 28 10:22 loop-control drwxr-xr-x 2 root root 60 Aug 28 10:22 mapper crw-r----- 1 root kmem 1, 1 Aug 28 10:22 mem crw------- 1 root root 10, 59 Aug 28 10:22 memory_bandwidth brw-rw---- 1 root disk 179, 0 Aug 28 10:22 mmcblk0 brw-rw---- 1 root disk 179, 1 Aug 28 10:22 mmcblk0p1 brw-rw---- 1 root disk 179, 2 Aug 28 10:22 mmcblk0p2 brw-rw---- 1 root disk 179, 5 Aug 28 10:22 mmcblk0p5 brw-rw---- 1 root disk 179, 6 Aug 28 10:22 mmcblk0p6 brw-rw---- 1 root disk 179, 7 Aug 28 10:22 mmcblk0p7 drwxrwxrwt 2 root root 40 Jan 1 1970 mqueue drwxr-xr-x 2 root root 60 Aug 28 10:22 net crw------- 1 root root 10, 61 Aug 28 10:22 network_latency crw------- 1 root root 10, 60 Aug 28 10:22 network_throughput crw-rw-rw- 1 root root 1, 3 Aug 28 10:22 null crw------- 1 root root 108, 0 Aug 28 10:22 ppp crw-rw-rw- 1 root tty 5, 2 Aug 29 17:23 ptmx drwxr-xr-x 2 root root 0 Nov 3 2016 pts brw-rw---- 1 root disk 1, 0 Aug 28 10:22 ram0 brw-rw---- 1 root disk 1, 1 Aug 28 10:22 ram1 brw-rw---- 1 root disk 1, 10 Aug 28 10:22 ram10 brw-rw---- 1 root disk 1, 11 Aug 28 10:22 ram11 brw-rw---- 1 root disk 1, 12 Aug 28 10:22 ram12 brw-rw---- 1 root disk 1, 13 Aug 28 10:22 ram13 brw-rw---- 1 root disk 1, 14 Aug 28 10:22 ram14 brw-rw---- 1 root disk 1, 15 Aug 28 10:22 ram15 brw-rw---- 1 root disk 1, 2 Aug 28 10:22 ram2 brw-rw---- 1 root disk 1, 3 Aug 28 10:22 ram3 brw-rw---- 1 root disk 1, 4 Aug 28 10:22 ram4 brw-rw---- 1 root disk 1, 5 Aug 28 10:22 ram5 brw-rw---- 1 root disk 1, 6 Aug 28 10:22 ram6 brw-rw---- 1 root disk 1, 7 Aug 28 10:22 ram7 brw-rw---- 1 root disk 1, 8 Aug 28 10:22 ram8 brw-rw---- 1 root disk 1, 9 Aug 28 10:22 ram9 crw-rw-rw- 1 root root 1, 8 Aug 28 10:22 random drwxr-xr-x 2 root root 60 Jan 1 1970 raw crw-rw-r-- 1 root netdev 10, 57 Aug 28 10:22 rfkill drwxr-xr-x 4 root root 80 Aug 29 16:11 serial lrwxrwxrwx 1 root root 7 Aug 28 10:22 serial1 -> ttyAMA0 drwxrwxrwt 2 root root 40 Aug 29 17:00 shm drwxr-xr-x 3 root root 180 Aug 28 10:22 snd lrwxrwxrwx 1 root root 15 Nov 3 2016 stderr -> /proc/self/fd/2 lrwxrwxrwx 1 root root 15 Nov 3 2016 stdin -> /proc/self/fd/0 lrwxrwxrwx 1 root root 15 Nov 3 2016 stdout -> /proc/self/fd/1 crw-rw-rw- 1 root tty 5, 0 Aug 28 12:13 tty crw--w---- 1 root tty 4, 0 Aug 28 10:22 tty0 crw------- 1 pi tty 4, 1 Aug 28 10:23 tty1 crw--w---- 1 root tty 4, 10 Aug 28 10:22 tty10 crw--w---- 1 root tty 4, 11 Aug 28 10:22 tty11 crw--w---- 1 root tty 4, 12 Aug 28 10:22 tty12 crw--w---- 1 root tty 4, 13 Aug 28 10:22 tty13 crw--w---- 1 root tty 4, 14 Aug 28 10:22 tty14 crw--w---- 1 root tty 4, 15 Aug 28 10:22 tty15 crw--w---- 1 root tty 4, 16 Aug 28 10:22 tty16 crw--w---- 1 root tty 4, 17 Aug 28 10:22 tty17 crw--w---- 1 root tty 4, 18 Aug 28 10:22 tty18 crw--w---- 1 root tty 4, 19 Aug 28 10:22 tty19 crw--w---- 1 root tty 4, 2 Aug 28 10:22 tty2 crw--w---- 1 root tty 4, 20 Aug 28 10:22 tty20 crw--w---- 1 root tty 4, 21 Aug 28 10:22 tty21 crw--w---- 1 root tty 4, 22 Aug 28 10:22 tty22 crw--w---- 1 root tty 4, 23 Aug 28 10:22 tty23 crw--w---- 1 root tty 4, 24 Aug 28 10:22 tty24 crw--w---- 1 root tty 4, 25 Aug 28 10:22 tty25 crw--w---- 1 root tty 4, 26 Aug 28 10:22 tty26 crw--w---- 1 root tty 4, 27 Aug 28 10:22 tty27 crw--w---- 1 root tty 4, 28 Aug 28 10:22 tty28 crw--w---- 1 root tty 4, 29 Aug 28 10:22 tty29 crw--w---- 1 root tty 4, 3 Aug 28 10:22 tty3 crw--w---- 1 root tty 4, 30 Aug 28 10:22 tty30 crw--w---- 1 root tty 4, 31 Aug 28 10:22 tty31 crw--w---- 1 root tty 4, 32 Aug 28 10:22 tty32 crw--w---- 1 root tty 4, 33 Aug 28 10:22 tty33 crw--w---- 1 root tty 4, 34 Aug 28 10:22 tty34 crw--w---- 1 root tty 4, 35 Aug 28 10:22 tty35 crw--w---- 1 root tty 4, 36 Aug 28 10:22 tty36 crw--w---- 1 root tty 4, 37 Aug 28 10:22 tty37 crw--w---- 1 root tty 4, 38 Aug 28 10:22 tty38 crw--w---- 1 root tty 4, 39 Aug 28 10:22 tty39 crw--w---- 1 root tty 4, 4 Aug 28 10:22 tty4 crw--w---- 1 root tty 4, 40 Aug 28 10:22 tty40 crw--w---- 1 root tty 4, 41 Aug 28 10:22 tty41 crw--w---- 1 root tty 4, 42 Aug 28 10:22 tty42 crw--w---- 1 root tty 4, 43 Aug 28 10:22 tty43 crw--w---- 1 root tty 4, 44 Aug 28 10:22 tty44 crw--w---- 1 root tty 4, 45 Aug 28 10:22 tty45 crw--w---- 1 root tty 4, 46 Aug 28 10:22 tty46 crw--w---- 1 root tty 4, 47 Aug 28 10:22 tty47 crw--w---- 1 root tty 4, 48 Aug 28 10:22 tty48 crw--w---- 1 root tty 4, 49 Aug 28 10:22 tty49 crw--w---- 1 root tty 4, 5 Aug 28 10:22 tty5 crw--w---- 1 root tty 4, 50 Aug 28 10:22 tty50 crw--w---- 1 root tty 4, 51 Aug 28 10:22 tty51 crw--w---- 1 root tty 4, 52 Aug 28 10:22 tty52 crw--w---- 1 root tty 4, 53 Aug 28 10:22 tty53 crw--w---- 1 root tty 4, 54 Aug 28 10:22 tty54 crw--w---- 1 root tty 4, 55 Aug 28 10:22 tty55 crw--w---- 1 root tty 4, 56 Aug 28 10:22 tty56 crw--w---- 1 root tty 4, 57 Aug 28 10:22 tty57 crw--w---- 1 root tty 4, 58 Aug 28 10:22 tty58 crw--w---- 1 root tty 4, 59 Aug 28 10:22 tty59 crw--w---- 1 root tty 4, 6 Aug 28 10:22 tty6 crw--w---- 1 root tty 4, 60 Aug 28 10:22 tty60 crw--w---- 1 root tty 4, 61 Aug 28 10:22 tty61 crw--w---- 1 root tty 4, 62 Aug 28 10:22 tty62 crw--w---- 1 root tty 4, 63 Aug 28 10:22 tty63 crw--w---- 1 root tty 4, 7 Aug 28 10:22 tty7 crw--w---- 1 root tty 4, 8 Aug 28 10:22 tty8 crw--w---- 1 root tty 4, 9 Aug 28 10:22 tty9 crw--w---- 1 root tty 204, 64 Aug 29 16:10 ttyAMA0 crw------- 1 root root 5, 3 Aug 28 10:22 ttyprintk crw-rw---- 1 root dialout 188, 1 Aug 29 16:11 ttyUSB1 crw------- 1 root root 10, 239 Aug 28 10:22 uhid crw------- 1 root root 10, 223 Aug 28 10:22 uinput crw-rw-rw- 1 root root 1, 9 Aug 28 10:22 urandom drwxr-xr-x 3 root root 60 Aug 28 10:22 v4l crw-rw---- 1 root video 243, 0 Aug 28 10:22 vchiq crw-rw---- 1 root video 248, 0 Aug 28 10:22 vcio crw------- 1 root root 249, 0 Aug 28 10:22 vc-mem crw-rw---- 1 root tty 7, 0 Aug 28 10:22 vcs crw-rw---- 1 root tty 7, 1 Aug 28 10:22 vcs1 crw-rw---- 1 root tty 7, 2 Aug 28 10:22 vcs2 crw-rw---- 1 root tty 7, 3 Aug 28 10:22 vcs3 crw-rw---- 1 root tty 7, 4 Aug 28 10:22 vcs4 crw-rw---- 1 root tty 7, 5 Aug 28 10:22 vcs5 crw-rw---- 1 root tty 7, 6 Aug 28 10:22 vcs6 crw-rw---- 1 root tty 7, 7 Aug 28 10:22 vcs7 crw-rw---- 1 root tty 7, 128 Aug 28 10:22 vcsa crw-rw---- 1 root tty 7, 129 Aug 28 10:22 vcsa1 crw-rw---- 1 root tty 7, 130 Aug 28 10:22 vcsa2 crw-rw---- 1 root tty 7, 131 Aug 28 10:22 vcsa3 crw-rw---- 1 root tty 7, 132 Aug 28 10:22 vcsa4 crw-rw---- 1 root tty 7, 133 Aug 28 10:22 vcsa5 crw-rw---- 1 root tty 7, 134 Aug 28 10:22 vcsa6 crw-rw---- 1 root tty 7, 135 Aug 28 10:22 vcsa7 crw-rw---- 1 root video 244, 0 Aug 28 10:22 vcsm crw-rw-rw- 1 root root 10, 58 Aug 28 10:22 vcsm-cma crw-rw---- 1 root tty 7, 64 Aug 28 10:22 vcsu crw-rw---- 1 root tty 7, 65 Aug 28 10:22 vcsu1 crw-rw---- 1 root tty 7, 66 Aug 28 10:22 vcsu2 crw-rw---- 1 root tty 7, 67 Aug 28 10:22 vcsu3 crw-rw---- 1 root tty 7, 68 Aug 28 10:22 vcsu4 crw-rw---- 1 root tty 7, 69 Aug 28 10:22 vcsu5 crw-rw---- 1 root tty 7, 70 Aug 28 10:22 vcsu6 crw-rw---- 1 root tty 7, 71 Aug 28 10:22 vcsu7 crw------- 1 root root 10, 137 Aug 28 10:22 vhci crw-rw----+ 1 root video 81, 0 Aug 28 10:22 video10 crw-rw----+ 1 root video 81, 1 Aug 28 10:22 video11 crw-rw----+ 1 root video 81, 2 Aug 28 10:22 video12 crw------- 1 root root 10, 130 Aug 28 10:22 watchdog crw------- 1 root root 251, 0 Aug 28 10:22 watchdog0 crw-rw-rw- 1 root root 1, 5 Aug 28 10:22 zero pi@rp3b:~ $
monojk
commented
3 years ago Make sure that you put RxD to TxD, and TxD to RxD on the Pi. Then you need to make sure your Pi has created the symbolic links in the system. Reboot, and check you MH-z19 for the Orange light. Make sure I2C is enabled as well. … On Sat, Aug 29, 2020 at 8:18 AM monojk @.***> wrote: The connection is according to the cabling in your README.md [image: 2020-08-29 16 12 20] https://user-images.githubusercontent.com/25121142/91638914-1b35a480-ea13-11ea-864a-d4e09e04b979.jpg — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#22 (comment)>, or unsubscribe https://github.com/notifications/unsubscribe-auth/AEBLRRNY5D2HDRVOIU5N62LSDEE2TANCNFSM4QO7BF3Q .
Hm, the orange LED ist off. Should it be on if power is attached and/or flashing during transfer?
UedaTakeyuki
commented
3 years ago Hi, nincube8!
Thank you for your support. I think your point is very good. Indeed, in the result of "ls -la /dev" there are no serial0, it indicates that UART might not be working.
Hi, monojk! As mentioned by nincube8, most doubtful causes are:
Please make sure and tell me the result. By the way, it's midnight in Tokyo (where I live), sorry I'll get to sleep soon and the next reply might be about 8 hours after :-) thank you for your understanding.
monojk
commented
3 years ago All, thanks for the hint. I thought I had enabled serial, but it wasn#T. Now I am a step further:
pi@rp3b:~ $ cat mh-z19.py
#!/usr/bin/python -u
import mh_z19
print(mh_z19.read())
print(mh_z19.read_all())and I get the following results. Notice that read() still returns None and sometimes there is an error:
pi@rp3b:~ $ sudo ./mh-z19.py
None
{'TT': 63, 'UhUl': 25856, 'SS': 0, 'temperature': 23, 'co2': 1441}
pi@rp3b:~ $ sudo ./mh-z19.py
Traceback (most recent call last):
File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 490, in read
'device reports readiness to read but returned no data '
serial.serialutil.SerialException: device reports readiness to read but returned no data (device disconnected or multiple access on port?)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/usr/local/lib/python3.5/dist-packages/mh_z19/__init__.py", line 63, in mh_z19
s=ser.read(9)
File "/usr/lib/python3/dist-packages/serial/serialposix.py", line 497, in read
raise SerialException('read failed: {}'.format(e))
serial.serialutil.SerialException: read failed: device reports readiness to read but returned no data (device disconnected or multiple access on port?)
None
{'temperature': 23, 'SS': 0, 'TT': 63, 'UhUl': 25856, 'co2': 1441}
It's a weird occurring serial reading error only in the mh_z19.read(), even not occurring it in mh_z19.read_all() which uses the same logic except for command string.
Indeed, on my side, the issue is not reproduced as follows:
pi@raspberrypi:~ $ cat mh-z19.py
#!/usr/bin/python -u
import mh_z19
print(mh_z19.read())
print(mh_z19.read_all())
pi@raspberrypi:~ $ sudo ./mh-z19.py
{'co2': 751}
{'SS': 235, 'UhUl': 10356, 'TT': 61, 'co2': 751, 'temperature': 21}I wonder there can be something instability of the serial connection, like loose physical cabling, unstable power supply, and so on.
nincube8
commented
3 years ago Not saying this will work, but it's helped me with sensors in the past. Try using a 5k pull up resistor across the Vcc and TxD, and if that doesn't work, try putting the resistor across the RxD and Vcc lines.
On Sun, Aug 30, 2020 at 2:19 AM Dr. Takeyuki Ueda notifications@github.com wrote:
It's a weird occurring serial reading error only in the mh_z19.read(), even not occurring it in mh_z19.read_all() which uses the same logic except for command string.
Indeed, on my side, the issue is not reproduced as follows:
pi@raspberrypi:~ $ cat mh-z19.py
!/usr/bin/python -u
import mh_z19 print(mh_z19.read()) print(mh_z19.read_all()) pi@raspberrypi:~ $ sudo ./mh-z19.py {'co2': 751} {'SS': 235, 'UhUl': 10356, 'TT': 61, 'co2': 751, 'temperature': 21}
I wonder there can be something instability of the serial connection, like loose physical cabling, unstable power supply, and so on.
— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/UedaTakeyuki/mh-z19/issues/22#issuecomment-683391377, or unsubscribe https://github.com/notifications/unsubscribe-auth/AEBLRRMZJO456KEP4T4LRXLSDIDPXANCNFSM4QO7BF3Q .
nincube8
commented
3 years ago Make sure that the MH-z19 is lighting up, it has a little laser inside it and if it's getting good power it will light up orange, that will tell you if the voltage is good or not.
On Sun, Aug 30, 2020 at 2:40 AM CK Gaming Channel cevatkose@gmail.com wrote:
Not saying this will work, but it's helped me with sensors in the past. Try using a 5k pull up resistor across the Vcc and TxD, and if that doesn't work, try putting the resistor across the RxD and Vcc lines.
On Sun, Aug 30, 2020 at 2:19 AM Dr. Takeyuki Ueda < notifications@github.com> wrote:
It's a weird occurring serial reading error only in the mh_z19.read(), even not occurring it in mh_z19.read_all() which uses the same logic except for command string.
Indeed, on my side, the issue is not reproduced as follows:
pi@raspberrypi:~ $ cat mh-z19.py
!/usr/bin/python -u
import mh_z19 print(mh_z19.read()) print(mh_z19.read_all()) pi@raspberrypi:~ $ sudo ./mh-z19.py {'co2': 751} {'SS': 235, 'UhUl': 10356, 'TT': 61, 'co2': 751, 'temperature': 21}
I wonder there can be something instability of the serial connection, like loose physical cabling, unstable power supply, and so on.
— You are receiving this because you commented. Reply to this email directly, view it on GitHub https://github.com/UedaTakeyuki/mh-z19/issues/22#issuecomment-683391377, or unsubscribe https://github.com/notifications/unsubscribe-auth/AEBLRRMZJO456KEP4T4LRXLSDIDPXANCNFSM4QO7BF3Q .
monojk
commented
3 years ago Hi nincube8, the 4.7k pull up resistor across the Vcc and TxD helped. Now I am also getting a result from read(). Thanks.
The orange LED still doesn't light up. I measure a Vcc voltage of 4.8V
Thanks also to UedaTakeyuki for help.
On my Raspberry 3B+ I get None from
mh_z19.read()and 9 frommhz_19.read_all()I am using Python3.6 The serial is/dev/serial1 -> ttyAMA0The mh_z19 is connected RxD <-> TxD and TxD <-> RxD (physical pins 8 and 10)There is also another module (SDS011) connected to USB.
Any suggestion for debugging?