axp192 LoRa ( sx1276 ) Voltage

[Internetwurm]

Hello @all,

i just added the set Voltage reading to the serial.printf block to take a look what is configured. I discovered that for Channel 2 ( DCDC2 sx1276 channel ) it was set to 1.250V ( 1250 raw value). Setting it to 1.850V doesn´t make it connect to ttn. But with purely underpowered it could make a difference. Maybe it will need full Voltage to send for more far distance.

The adjusted block: Serial.printf("DCDC1: %s\n", axp.isDCDC1Enable() ? "ENABLE" : "DISABLE"); Serial.printf("DCDC1 Voltage: %d\n", axp.getDCDC1Voltage()); Serial.printf("DCDC2: %s\n", axp.isDCDC2Enable() ? "ENABLE" : "DISABLE"); Serial.printf("DCDC2 Voltage: %d\n", axp.getDCDC2Voltage()); if(axp.getDCDC2Voltage() < 1800) { axp.setDCDC2Voltage(1850); //sx1276 needs 1.8 Volte at least, so something extra for suitable powering delay(100); // not sure if it is really needed Serial.printf("NEW DCDC2 Voltage: %d\n", axp.getDCDC2Voltage()); }

  Serial.printf("LDO2: %s\n", axp.isLDO2Enable() ? "ENABLE" : "DISABLE");
  Serial.printf("LDO2 Voltage: %d\n", axp.getLDO2Voltage());
  Serial.printf("LDO3: %s\n", axp.isLDO3Enable() ? "ENABLE" : "DISABLE");
  Serial.printf("LDO3 Voltage: %d\n", axp.getLDO3Voltage());
  Serial.printf("DCDC3: %s\n", axp.isDCDC3Enable() ? "ENABLE" : "DISABLE");
  Serial.printf("DCDC3 Voltage: %d\n", axp.getDCDC3Voltage());
  Serial.printf("Exten: %s\n", axp.isExtenEnable() ? "ENABLE" : "DISABLE");
  Serial.printf("Battery Voltage: %d\n", axp.getBattVoltage());
  Serial.printf("BAttery Percentage: %f\n", axp.getBattPercentage());
  Serial.printf("Battery Charge Current set: %d\n", axp.getSettingChargeCurrent());
  Serial.printf("Chip Temp: %d\n", axp.getTemp());
  Serial.printf("Chip TSTemp: %d\n", axp.getTSTemp());

[Internetwurm]

ah yes i missed to make a proofing picture from voltage value before. Maybe it also differs between Models. I am using the V1.0.

[Internetwurm]

God damn! Set it to 2.275V for LoRa and rechecked my keys

IT WORKED!

[kizniche]

Excellent investigative work! Could you tell me the exact change you made for the fix so I can replicate, test, and update the code?

[kizniche]

Is it axp.setDCDC2Voltage(2275); ?

[Internetwurm]

Okay i try to reveal my way.

On configration.h changed values form default:

"PAYLOAD_FULL" LORAWAN_CONFIRMED_EVERY 10 LORAWAN_SF DR_SF12 // I am 15km off the next gateway ;-) LORAWAN_ADR 1

Except the last two values it shouldn´t change anything important.

On "credentials.h"

define USE_ABP Fiddeling with endian keys several times, maybe i am too old.

Nothing else here. All other unchanged, just added +1 hour for GPS time in "gps.h".

In my opinion the most important change comes here for sx1276 module voltage supply. On "main.h"

i added at if (axp192_found) { ... //first serial.printf block //axp.setPoweOutPut statements //second Serial.printf block I added ( insetered ) the commands from first post.

...} I used reference Document to reveal command to read and set values from the "AXP202X_Library" at "/src/axp20x.cpp". Then i added them to just read the set values. After first run i added the if query to adjust DCDC2 voltage to ( now ) maximum 2.275V ( 2275 ).

With ABP i was able to send at least one packet over 15km with default delivered antenna. Very impressive thing.

For reference the Link to axp chip family document.

https://github.com/m5stack/M5-Schematic/blob/master/Core/AXP192%20Datasheet_v1.1_en_draft_2211.pdf

So far, as i changed to OTAA now it doesn´t seem to reconnect. If i set sleep time and reset it starts up and go to sleep admideatly. Maybe a wating loop or time is needed here. Also it could take some time to hit a gateway with the send packets.

But as shown with ABP at least it was a proof that your sketch is working. Maybe i have to give it a try with CLOCK_ERROR to get it reliable work for a time.

Thanks for your work. Hopefully you will transfer this to be used with ESP-IDF soon? ;-) Just joking.

[Internetwurm]

[netmonk]

Im far away from any gateway right now, so basically i wont be able to test anything before end of week But looks promising.

[Internetwurm]

Hey Beamer Folks,

as it seems OTAA doesn´t work for me for this far distance. I got no luc in Joining with OTAA.

I will try to keep up with that but for now i hang off from this until i get at least a one channel gateway here. Doesn´t make sense without it. It is not reliable in this constellation caused by the huge distance.