Getting TWR example to work

[gilbertgit]

Hello, I'm trying to use libdeca with my setup. I have a board with a dwm3000 and an esp32c6. Looks like SPI coms are good but I'm having a hard time getting the devices to range. Here are some of init functions:

dwmac_init(0x1234, 0x0001, 10, twr_rx_handler, timeout_cb, err_cb);
twr_init(DWT_BR_6M8, DWT_PLEN_64, DWT_PRF_64M);

 // two way ranging to two destinations
 uint16_t dst[] = {0x1001};
 twr_start(dst, 1, 1, res, sizeof(res), twr_done_cb, false);

My other device has an ID of 0x1001 and sending to 0x0001. Is this the correct approach? Here is an example of my logs are looking like:

I (400) DW3000: RESET:21 WAKEUP:22 IRQ:23
I (400) gpio: GPIO[21]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0 
I (400) gpio: GPIO[22]| InputEn: 0| OutputEn: 1| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:0 
I (410) DW3000: SPI Init (MOSI:7 MISO:2 CLK:6 CS:5)
I (410) INIT: DWM INIT SUCCESS
I (420) DW3000: HW reset
I (420) gpio: GPIO[23]| InputEn: 1| OutputEn: 0| OpenDrain: 0| Pullup: 0| Pulldown: 0| Intr:1 
I (430) DECA: DEV ID: DECA0302
I (430) gpio: GPIO[5]| InputEn: 0| OutputEn: 0| OpenDrain: 0| Pullup: 1| Pulldown: 0| Intr:0 
I (440) DECA: config CH 9 6.8Mbps PRF 64MHz Plen 64 PAC 8
I (450) DECA: config code 11/11 SFD 65
I (450) DECA: PRE 66 (SFD 9) PHD 22 12B DATA 19 = 114 us
I (460) DECA: Init PANID: 1234 MAC: 0001
I (460) DWTASK: TASK started
I (470) TWR: delay 792 us RX delay 678 us PTO 8 (66 us)
I DECA: *** RX Timeout 2200001
E (480) TWR: RX timeout from 1001
I (490) TWR: retry 1 to 1001 after 13 ms
I DECA: *** RX Timeout 200001
I (490) timeout_cb: Timeout
E (490) TWR: RX timeout from 1001
I (490) TWR: retry 2 to 1001 after 3 ms
I DECA: *** RX Timeout 200001
I (500) timeout_cb: Timeout
E (500) TWR: RX timeout from 1001
E (510) TWR: retry limit exceeded 1001
I (510) twr_done_cb: TWR Done 1001: 65535 cm
I (520) timeout_cb: Timeout

I appreciate your help!

[br101]

Is the other side in RX mode?

[gilbertgit]

Both of the devices are running the exact code except for the mac address on dwmac and the dst array are swapped. What's the best way to tell if a device is in RX mode.

[gilbertgit]

I was able to get the other device in receive mode by using dwt_rxenable(DWT_START_RX_IMMEDIATE); and it is now getting something. But it looks like it's stuck stuck when trying to respond.

I DECA: *** RX 2006f01 flags 5
E (4983) DECA: TX error seq 0 (0x4080e1a0)
E (4983) DECA:  SYS Time:       442f907a00
E (4993) DECA:  TX Time:        442ea48234
E (4993) DECA:  Diff:           ff140834 (-242 us)
E (4993) TWR: Failed to send Response to 1001
I (5003) TWR: rx_ts442ba04f01
I (5003) TWR: tx_ts442ea48234
I (5013) TWR: delay0003043333

The sender still retries as it was doing before:

I DECA: *** RX Timeout 200001
E (114053) TWR: RX timeout from 0001
I (114053) TWR: retry 1 to 0001 after 0 ms
I DECA: *** RX Timeout 200001
I (114063) timeout_cb: Timeout
E (114063) TWR: RX timeout from 0001
I (114073) TWR: retry 2 to 0001 after 8 ms
I DECA: *** RX Timeout 200001
I (114073) timeout_cb: Timeout
E (114083) TWR: RX timeout from 0001
E (114083) TWR: retry limit exceeded 0001
I (114093) twr_done_cb: TWR Done 0001: 65535 cm
I (114093) timeout_cb: Timeout

An example of what both device setups would look like would be helpful.

[br101]

It seems your microcontroller is too slow to meet the timing requirements. Increase TWR_PROCESSING_TIME by at least 250 in ranging.c on both sides. It can also help to reduce the logging in dwmac_irq.c ("*** RX 2006f01 flags 5").

[br101]

An example of what both device setups would look like would be helpful.

True, I added it to the README

[gilbertgit]

That's very helpful. Thank you for your help!

[br101]

So did you get it to work finally? I'm very interested to get feedback on the usability of the library. Thanks!