XIAO Expansion Board & Base for Battery

[cgwaltney]

Expansion Board Base for XIAO Level Battery

Hi there, Ok , so I looked around and I See this info. The standard Meshtastic battery reading system works by using an internal voltage divider circuit connected to an Analog-to-Digital Converter (ADC) pin on the microcontroller. This setup allows the device to measure the voltage of the connected battery and report it via the Meshtastic app and display. How the battery reading works Voltage divider: A voltage divider is a simple circuit made of two resistors. Its purpose is to lower the b…

Seeed Studio XIAO nRF52840 Potentiostat and output levels

I’m currently working on a noninvasive wearable, sweat-based microfluidic glucose sensor. My system uses a screen-printed carbon working electrode (WE/RE/CE), An LMP91000 potentiostat for current-to-voltage conversion, A Seeed Studio XIAO nRF52840 microcontroller for ADC and Bluetooth transmission, and a 3.7 V Li-ion battery as the power source. Does anyone know if the Seeed Studio XIAO nRF52840 is compatible with the LMP91000 as a potentiostat?

Battery voltage monitor and AD conversion for XIAO_ESP32C

The battery pad of XIAO_ESP32C3 is not connected to any port, so the battery voltage cannot be read and there is a risk of over-discharging the battery. (XIAO_BLE has a port connected to the pad and can read the voltage.) The battery voltage was divided by 1/2 with 200k and connected to the A0 port so that the voltage could be monitored. About the AD conversion of the ESP32C3 The datasheet says nominally 2500mV full scale AD conversion, but there is a large variation from chip to chip, actua…

Soldering XIAO BLE battery pads with through hole

Hi, I’m designing a PCB for the XIAO BLE. As part of this, I want to use the battery terminals on the rear. As I don’t have a reflow or hot air station, I’m forced to use a through hole approach. I tried the official Seeed KiCAD footprint, but it wasn’t very reliable. For the 2nd variation on my design, I made the plated through holes into larger oval shapes, but that didn’t work properly either (my first attempt only connected to + terminal) [image] Now, my soldering technique isn’t great …

Seeed Studio XIAO ESP32S3 Sense - battery problem

Hello, this is my first encounter with Seeed Studio XIAO ESP32S3 Sense and I don’t have much experience with these gadgets. I programmed the Seeed Studio XIAO ESP32S3 Sense to take pictures every 3 seconds and save them to the sd card, but it only happens when the board is powered via the usb-c port. When I power the board through a battery connected to the rear pins, there is no indication of life. When I connect the battery and usb cable to the board, the device works and indicates that the …

Current leak using a voltage divider with the XIAO ESP32-C6

Below is my setup for reading the USB voltage and battery voltage. Do I need to worry about any current leak here through the battery voltage divider which may impact battery life? I was considering adding a transistor connected to an output pin which would enable the battery voltage divider only when the voltage needs to be read. I am not sure if it is really required though. [schematic-voltage-dividers]

Powering the XIAO nRF52840 via supercaps

Hi everyone! I’m working on my University thesis project which consists in a battery-less heart rate monitor, powered by different energy sources which charge up a supercapacitor. I’m planning on hooking up a XIAO nRF52840 to the supercap, and an AD8232 HR sensor board to the Xiao. At this point I’m not sure whether I should be using the BAT pins connected to the battery charge chip or the 3.3V/GND pins on the board. What do you guys suggest? I can give you more info if you ask. Thanks in adva…

Soldering of BAT and Thermal pads on ESP32-C3 to a motherboard

The BAT pads are on the back of the XIAO ESP32-C3 which makes surface mount soldering to a mother board problematic. There is also a thermal pad, which I presume is the heat sink for the battery charger IC which may benefit from being soldered to the ground plane of the motherboard. Can anyone please suggest how these pads might be soldered to a mother board by hand? My thought was to add vias on the mother board so solder can be applied to the back of the mother board and wick through to the BA…

Detecting USB or battery power

Hi all. I have decided to use the XIAO-ESP32-C6 devices in my projects. So far they are great. How can I detect in my software if there is USB power being provided or not? As I would like to have this as a readable Matter attribute to determine if my device is just being battery-powered, or charging via USB. I am using ESP-IDF and and ESP-Matter repositories for this (Not Arduino). Thanks in advance

Xiao nrf52840 board with Xiao expansion board short circuit

I had been using the xiao_ble board with the xiao_expansion shield with vanilla zephyr and so far things worked as they should. I could do the basic stuff – GPIO, OLED, Buzzer, etc., Yesterday, I enabled support for mcuboot bootloader and USB DFU support for firmware upgrades and the board stopped working a while after I flashed the firmware with USB device support (I verified that the firmware indeed exposed a USB DFU class). When I say not working, I mean: LED stoped blinking and jlink can no…

Part number for JST power connector

I wonder if anyone can give me the part number for the JST power connector which mates with the onboard connector found on the Seeeduino. I think I actually need two numbers: one for the housing and one for the crimp pins. I am aware that this connector is available with pigtail wires from the Seeed Studio Depot.

How to detect disconnection from USB and how to keep the radio active on battery

Ok, so I’m using a XIAO 52840 Sense with a battery connected to the VBAT pad on the bottom, and everything is almost working as expected. Almost. When I disconnect the device from USB, one main problematic thing happens: I lose radio connectivity. I have to power down the radio, power back up and re-apply configuration I am using the nrf_to_nrf library for the radio but I suspect simlar behaviour with bluetooth. I am wondering two main things: a. Can I prevent the radio from dying out when…

XIAO Expansion - battery connector backwards?

As noted in other posts, it appears the LIPO battery connector is backwards / opposite of every connector / battery leads I’ve ever seen. Can anyone confirm that the negative and positive terminals are indeed accurate as labeled on the board and on the product page? I don’t want to burn this thing out because a board was misprinted. If I plug a battery in the only way it will fit the polarity will be reversed.

[cgwaltney]

[cgwaltney]

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