Originally designed as a charity project, the MWR is a simple single-station battery powered internet radio. The design features a combined power-volume dial and 3.5mm headphone socket, utilising a 3D printed case

Firmware, documentation and STL files: https://github.com/AllanGallop/mini-web-radio

Don't want the battery? follow the steps below omitting the battery, battery LED, power circuit and connect the switch side of the potentiometer between 3v and GPIO 33 pins, finally use the "no-battery" branch firmware files found here:

https://github.com/AllanGallop/mini-web-radio/tree/no-battery

Supplies

Parts

1x WeMos Lolin32 Lite (ESP32)
1x MAX98357A
1x 10K Linear Potentiometer with SPST switch
2x 47K 1/4W Resistor
2x 330R 1/4W Resistor
2x 3mm LED
1x18650 Battery and Holder
2x M1.7 5mm pan head screw
1x M2 5mm flat heat screw
1x 3D Printed Case Shell
1x 3D Printed Case Face
1x 3D Printed Volume Knob
Various guages of wire
Various sizes of heatshrink tubing

Tools

Soldering Iron
Wire Cutters
Hot-Glue Gun

Step 1: Prepare ESP32

Carefully desolder the battery connector and clean the pads
Solder ~4" of wire (Red and Black preferred) onto the battery pads as pictured
Install 2x 2.54mm header into pads labelled 13 & 15

Step 2: Prepare Max98357A Module

Cut one pin of the supplied 2.54mm header so that only 6 pins remain
Locate the header onto the module so that VIN pin remains unpopulated
Solder the header to the board
Solder ~6" of wire (red preferred) to the VIN pad of the module
Attach the 2 pin screw terminal to the module

Step 3: Prepare Battery Holder

Solder a 47K resistor to the studs at either end of the battery holder
Cover each resistor with a length of heat shrink tubing
Carefully bend the resistor legs around the body of the battery holder
Solder the ends of the resistors together along with 4" length of wire
Carefully heat the tubing to shrink it

Step 4: Connect Audio Module to ESP32

Carefully align the Max98357 module so that the Gnd pins align
Solder the module in place
Flex the flying lead under the module and solder to 3v3 pin
Place a small blob of hot glue to retain the flying lead if needed

Step 5: Connect Switch

Cut a short length of tined wire and create a bridge on the potentiometer between one of the switch legs (rear) and one side of the potentiometer as pictured
Attach red battery wire to the leg bridged previously
Attach red ESP32 wire to the opposing switch leg (pictured)
Cut a 2" length of black wire
Locate both black wires from the ESP32 and Battery holder
Slip a short length of heatshrink over the bundle of 3 wires
Solder the bundle to the opposing leg on the potentiometer as pictured
Attach ~4" of wire (yellow preferred) to the wiper leg of the potentiometer
Secure Potentiometer to faceplate

Step 6: LED's

Secure LED's to faceplate with hotglue
Flex cathode legs of the LED's so that they overlap and solder them together
Solder black wire from Step 5 (Switch) to LED cathode
Trim LED cathode legs to ~10mm
Attach a ~4" length of wire to each LED cathode
Solder flush & upright both remaining (330R) resistors into pads 5 & 18 respectfully as pictured
Trim the exposed resistor legs to ~10mm
Attach LED wires created ealier to each resistor
Solder Battery sense wire to pad 33 on the ESP32
Solder Volume sense wire to pad 34 on the ESP32