TX pin is initialized high after startup

[Scrath1]

Hello,
while viewing the signal of my transmitter using an SDR, I noticed that after startup of the raspberry pi, the TX pin of the transmitter is apparently initialized to high and a continuous signal is being sent.

The continuous transmission stops after the first command is manually sent. In my case I used a stop command.

Measuring the transmission pin with a multimeter confirms this. Until the first command is sent, the pin is at ~3.3V and afterwards drops to 0V.

I am using a Raspberry Pi 1 model B.

[arthurdent2095]

I have always had the same problem and have a scheduled command at 2am to close a blind right after a reboot.

But also, over time I am finding my transmitter boards stop working properly after about a year each. It's as if they drift off frequency slightly, putting a finger on the board makes them work again, but they were fine from new. I think this behaviour with the GPIO does not help extend their life.

If there is no fix yet, this time I am motivated to fix it in case it extends the life of the transmitter.

See Issue 120. You have same issue on Pi 1B ; I have Pi Zero W

Edit: I found a fix here.
https://www.electro-tech-online.com/threads/them-pesky-cheapo-433mhz-transmitters.143245/page-2
By soldering a small capacitor on the back of the board as per the very last post on that thread from doar2d, my transmitter is fixed.

Edit: the first call that I can see in the code for set_mode() is in sendCommand() as opposed to in the initialiser startPIGPIO in operateShutters which just calls pigpio.pi(). I think the set_mode() call needs to be removed from sendCommand, moved into startPIGPIO, and possibly also need to write a 0 in the initialiser. When I have time, I will try this, the problem I have is up until the first send command, my normal remotes don't work.