The Tx Power of 51822 varies and getting weaker and weaker

[Daliwan]

We are building a simple project, let 51822 connect the mobile, once per second. We found that the Tx power of 51822 is getting weaker and weaker (view the voltage over a 10Ohm resistor which is connected in the circuit by Oscilloscope)，after a few minutes, the signal is so weak that it loses the connection with the mobile. Could you help me to explain this and find the solution? Thank you.

Best regards,

[ovrebekk]

Hi Daliwan

I don't understand what you are measuring. Are putting a 10 Ohm resistor in series with the VDD line, and measuring the current into the chip?

Are you using a custom board or one of the devkits?

Are you using a battery, and if so which type?

Do you know how well the code is power optimized? Have you tested with one of the standard SDK examples for reference?

Best regards
Torbjørn

[Daliwan]

First, yes, you are right, we are using an Oscilloscope to measure the voltage over the 10Ohm, which is connected in series between Vcc and the system, so that we can estimate the current consumption. Second, we tried both battery and voltage source. We are not using kit board, but a board we developed by ourselves. The board is quite simple, a 51822 module and another module, which is turned off in normal. It will be turned on when 51822 loses the connection. A kind of anti-lose system. We use the SDK UART example and only use the connection function of it. Thanks.

[ovrebekk]

Do you have more than one board to test?
Can you share the schematics, and maybe a picture of your board?

Best regards