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Can't set the RF tx power

Open oangelo opened this issue 4 years ago • 6 comments

I am tring to set the tx power on Telink Flasher, but, when I press the button "Send Config" the minimum power is automaticaly set. "Set default" and then "Send Config" works to go back to the default. I wish to improve the tx power to be able to receive the data a bit more distant from my bluetooth hub. This hapens both in my smartphone and on a linux browser.

oangelo avatar Mar 09 '21 21:03 oangelo

? image

pvvx avatar Mar 10 '21 09:03 pvvx

Today it is working, thanks @pvvx. But, I can not choose the power higher than +3.01 dbm, only lower. Higher power options were showing yesterday. Is 3.01dbm the maximum power?

oangelo avatar Mar 10 '21 14:03 oangelo

The microcircuit has 2 antenna options (VBAT and VANT) and an RF power supply. The second option works with reduced power on the current board ... The CR2032 is not capable of generating large surge currents.

pvvx avatar Mar 11 '21 09:03 pvvx

So what is the highest power setting that can be achieved on the LYWSD03MMC ?

ibamsey avatar Mar 22 '21 17:03 ibamsey

So what is the highest power setting that can be achieved on the LYWSD03MMC ?

Depends on the internal resistance of the battery. The chip has tx output power up to +10 dB The original firmware has a maximum transmit power of 0 dB.

On more or less CR2032, when setting +3.1 dB (max in VANT mode.), we have a power failure (> 170 mV): image

But this is the maximum work from the stabilizer built into the chip - VANT mode. High powers are obtained when the RF is powered directly from the battery (VBAT mode).

The VBAT mode is excluded in the latest versions of the configurator due to the questions "why doesn't it work?".

https://www.dmcinfo.com/Portals/0/Blog%20Files/High%20pulse%20drain%20impact%20on%20CR2032%20coin%20cell%20battery%20capacity.pdf

pvvx avatar Mar 22 '21 19:03 pvvx

Replacing the CR2032 with a more powerful battery allows for higher TX RF power to +10 dB. A pulse current of 30 mA is required at 3.3 V. In TelinkMiFlasher.html, change line: const MAX_RF_TX_Power = false; to const MAX_RF_TX_Power = true; image

pvvx avatar Dec 12 '21 10:12 pvvx