Dear hippy,
Thank you very much for your valuable information. Thanks to you, I was able to find the relevant article.
Original English excerpt:
"Note that on Pico W, the WiFi chip is connected to the ADC reference voltage via a multiplexer, and this can cause ADC readings to be inaccurate or noisy, especially when WiFi is active. This is a hardware limitation."
日本語訳
「Pico W では、WiFiチップがマルチプレクサ経由でADCのリファレンス電圧に接続されており、特にWiFiが動作中はADCの値が不正確になったりノイズが増えたりすることがあります。これはハードウェア上の制約です。」
Here is the script I used, which successfully publishes to MQTT using Wi-Fi. I am able to measure the voltage very stably within about ±0.02V.
Thank you for your precious time!
Thank you very much for your valuable information. Thanks to you, I was able to find the relevant article.
Original English excerpt:
"Note that on Pico W, the WiFi chip is connected to the ADC reference voltage via a multiplexer, and this can cause ADC readings to be inaccurate or noisy, especially when WiFi is active. This is a hardware limitation."
日本語訳
「Pico W では、WiFiチップがマルチプレクサ経由でADCのリファレンス電圧に接続されており、特にWiFiが動作中はADCの値が不正確になったりノイズが増えたりすることがあります。これはハードウェア上の制約です。」
Here is the script I used, which successfully publishes to MQTT using Wi-Fi. I am able to measure the voltage very stably within about ±0.02V.
Code:
Pin(25, Pin.OUT, value=1)Pin(29, Pin.IN, pull=None)time.sleep(0.1) # Wait 0.1 secondsraw = ADC(3).read_u16()voltage = raw * 3.3 / 65535vsys = voltage * 3 Pin(29, Pin.ALT, pull=Pin.PULL_DOWN, alt=7)Pin(25, Pin.OUT, value=0, pull=Pin.PULL_DOWN)return vsysThank you for your precious time!
Statistics: Posted by chanken — Mon Jun 16, 2025 6:44 am