Trying to understand CRTP Logging

[JVProdc]

Hello,

I'm trying to get telemetry data from Crazyflie to Multiprotocol radio using the CRTP protocol. I have troubles with getting correct data from the ACK packet.

Following the Logging documentation, I have successfully gone thru the TOC and get correct IDs of variables I want to log. But when I create the Log block and start it, on port 5 channel 2 I get wrong values and length of the received payload. Only thing, that seems correct is the header (82 - for port 5, channel 2) and Block ID (whatever I choose). The payload length increases with additional log variables, but I'm getting more bytes than expected and the values do not resemble what I would expect.

@ataffanel would you be able to help?

Used Multiprotocol repo here
Collaborating with @matejkarasek on this.

Any help appreciated

[JVProdc]

For example, I created block with packet:
header (port 5, channel 1), command 0 (creating the Log block), ID of the block (1), variable "isConnected" (111) , variable type (uint8_t corresponds to 1). Sample of the created packet:
(82, 0, 1, 111, 1).
Expected received packet (6 bytes long): header, block ID, 3 bytes of timestamp, value (1 - the CF is connected), but getting packet: header, block ID, 3 bytes of timestamp, -4 nonsense values -. The received packet is 9 bytes long.

[matejkarasek]

Thanks @ataffanel for the quick response, the example should certainly help!
We will report back...

[JVProdc]

Thank you @ataffanel, this was really helpful. We had not been sending the RESET command, which likely caused conflicts. Now it works as expected.
We also noticed your script uses the Log Block API V2 (command bytes 0x05, 0x06, instead of 0x00 - 0x05 shown in the doc) . Are there any major differences between V1 and V2 besides different command bytes?
Thank you for your help

[ataffanel]

The main difference is that V1 only supports up to 256 variables, while V2 uses 2 bytes for ID and so can handle 64Ki variables. We should likely remove V1 from the firmware as we have now more than 256 variables and it does not make any sense to keep the old API (it was kept for ease the transition).

[JVProdc]

Thank you for the explanation. My implementation of v1 API structure works fine, but when we tried to implement v2 API, it do not work. Is the ACK packet with data structured same in v2 as it is in v1?
Thank you

[ataffanel]

The V2 answer should be similar unless they contain IDs. I would suggest you use the V2 as much as possible though, now that I have my nose in it I will be tempted to remove the V1 packets to avoid any unnecessary confusion in the future. Until we get the documentation in a decent state, you can always look at the code to see what you are supposed to receive. The code is basically organized as one function per command so it should be not too bad to follow: https://github.com/bitcraze/crazyflie-firmware/blob/f52c50cbbec817cfdf01d06452f125923ac14565/src/modules/src/log.c#L470