Pcf8583 params not showing up in QGC

RayanR · December 19, 2020, 7:52pm

Hy,

I got a pcf8583 tachometer and wanted to connect it to my Holybro pixhawk 4. I noticed the parameters as listed here were not found in QGC. As the site suggested, i added rpm/pcf8583 to the cmake file for the board and builded it. after uploading the latest version to the pixhawk 4, it still not showed up in QGC. I looked into the parameter.xml file in the build folder, it had the specified parameters. when looking in the ParameterFactMetaData in from QGC, it also has those parameters, but still it is not showing up in the GUI of QGC.

I also tried installing the latest stable version of PX4 onto the board, but that didn’t change anything.

anybody knows what i could do? I installed the developer toolchain so i can edit files and make custom firmware.

thnx in advance,
RayanR

roman-dvorak · December 20, 2020, 12:50pm

Hi @RayanR, thanks for your question,

Driver was tested with our TFRPM01 sensor board. With what hardware/sensor are you testing it?

The latest stable version of PX4 should contain that driver. The driver is not automatically started. here we are working on updating the sensor documentation. (we will create a PR into the official documentation on docs.px4 in a few days). Our working version is here:

github.com

ThunderFly-aerospace/PX4-user_guide/blob/tf/tfrpm_doc_update/en/sensor/thunderfly_tachometer.md#starting-driver

# ThunderFly TFRPM01 Revolution Counter

The [TFRPM01](https://github.com/ThunderFly-aerospace/TFRPM01) tachometer is a small, and low system demanding revolution-counter.

The board itself does not include the actual sensor, but can be used with a number of different sensors/probe types for revolution counting.
It has an I²C connector for connecting to PX4, and is connected to the actual sensor via a 3-pin connector.
It also has an LED that offers basic diagnostic information.

![TFRPM01A](../../assets/hardware/sensors/tfrpm/tfrpm01_electronics.jpg)

:::note
The TFRPM01 sensor is open-source hardware commercially available from [ThunderFly s.r.o.](https://www.thunderfly.cz/) (manufacturing data is [available on GitHub](https://github.com/ThunderFly-aerospace/TFRPM01)).
It is based on the [PCF8583 counter](https://www.nxp.com/docs/en/data-sheet/PCF8583.pdf).
:::

## Hardware Setup

The board is equipped with a (two troughpass) I²C connectors for connecting to PX4 and has a 3-pin connector that can be used to connect to various sensors:
- TFRPM01 may be connected to any I²C port.
- TFRPM01 has 3pin pin-header connector (with pull-up equipped input) that can be connected to different probe types.

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In the current airframes, the driver does not start automatically. This is mainly due to some missing features in the driver.

So, please, try:

start driver - How it starts is described in the sent document.
restart QGC (to reload parameters) and autopilot
set right parameter value.

RayanR · December 20, 2020, 5:59pm

Hy, tanks for the fast response.

I got it working. i have a reverse engineered RPM counter based on the TFRPM01 sensor. it uses the same RTC but a different reading setup.

i got the driver started using the console. i then used put pcf8583 start -X -b 1 in a etc/extra.txt to launch it on the i2cA port of the pixhawk 4.

because of that, the driver starts on boot and i can see the parameters in QGC. However, when going to mavlink Console and typing listener rpm -n 50 i can see the rpm value and it changes accorting to the irl rpm of the motor. However, i can’t seem to find it in the Mavlink Inspector tab of QGC

Thanks,

RayanR

N_J · June 21, 2022, 11:12am

Hello @RayanR ,
I am also facing the same issue, I managed to autostart the RPM sensor but the topic is not published in Mavlink inspector, Did you happened to close this issue ?

roman-dvorak · June 21, 2022, 3:19pm

Hi @N_J,

What version of FW do you use?
Is the sensor driver running? You can check it in console by command pcf8583 status.

N_J · June 22, 2022, 7:56am

Hi @roman-dvorak I was using v1.12.3, i was able to read through the mavlink console but the uorb topic was not published, hence mavlink inspector was not showing up corresponding message.
BTW do you know whether the driver pcf858 is implemented in v1.10.1 ?

roman-dvorak · June 22, 2022, 8:14am

I dont understand. What you are able to read trough mavlink console? Can you send some screenshot?

Yes, that’s quite likely. At the same time, several modifications/improvements were made later to the PCF8583 driver, which introduced, for example, support for multiple sensors at the same time or fixed some bugs.

N_J · June 24, 2022, 7:55am

In mavlink console i can see the driver running in i2c port with the polling freq.
Upon giving listener rpm in mavlink console i can see the rpm values.
Couple of observations,

The address given in PCF8583_ADDR is 80 (corresponds to 0X50) but, this is not shown on mavlink console while i type in pcf8583 status It shows 0x00.

Screenshot from 2022-06-24 11-54-291850×1082 315 KB
No RAW_RPM message in Analyze tools > Mavlink Inspector

Screenshot from 2022-06-24 11-49-561107×453 32.5 KB

roman-dvorak · June 24, 2022, 8:07am

How did you reach the condition that you have 3 instances running? Do you have a startup script on your SD card? What does he look like? I think the problem is caused by wrong I2C address in driver.

Are you able to see I2C device (PCF8583) on the bus?

Otherwise, you need to look for a message in the mavlink analyzer RAW_RPM

N_J · June 24, 2022, 8:33am

I have given pcf8583 start as the start up script in PX4 firmware itself without defining the bus, hence its running in 3 buses. Will that cause a problem ?

roman-dvorak · June 26, 2022, 5:03pm

Okay, so I would suggest finding out if the sensor is visible on the bus - command i2cdetect -b <bus number and possibly try another bus.