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, 1:23pm

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