How to build my mikroPhone

Follow these instructions to build and assemble the device and to build and upload both FE310 and ESP32 firmware.

1 Build a device

You need to make and assemble two PCBs — main board and display adapter

Schematic: main board, display adapter
PCB fabrication files: main board, display adapter
Board view: main board, display adapter
Bill of Materials: main board (PDF — ODS), display adapter (PDF — ODS)

Original KiCad design files can be found in source code repository (see below, step 5)

2 Assemble

To assemble the phone you will need:

main and display adapter boards already built in step 1
E50RG84885LWAM520-CA display
SIMCom SIM7600X-H or Quectel EC-25 mini PCIe module
Any Li-Ion or Li-Po 3.6/3.7V battery

Locate DISPLAY connector at the bootom side of the board and connect display adapter board to it:

display adapter

Connect display panel to J2 and J3 connectors on display adapter board:

display panel

Insert cellular modem into mini PCIe connector:

modem

Locate BAT connector at the bootom side of the board and connect battery to it:

battery

3 Connect JTAG/UART programmer

This device supports FT2232H-56Q Mini Module for flashing both FE310 and ESP32 firmware. Connect FT2232H-56Q to J205 connector using 12 pin FFC breakout board according to folowing table:

J205 Pin	FT2232H-56Q Pin
1. `ESP32.UART0.RXD`	`BD0`
2. `ESP32.UART0.TXD`	`BD1`
3. `GND`	`GND`
4. `JTAG_TCK`	`AD0`
5. `JTAG_TDO`	`AD2`
6. `JTAG_TMS`	`AD3`
7. `JTAG_TDI`	`AD1`
8. `JTAG_TRST_N`	`AD5`
9. `GND`	`GND`

Leave other pins unconnected.

Alternatively, you can make FT2232H-56Q adapter board from hw/prog KiCad project directory and connect it using 12 conductor 0.5mm pitch FFC jumper cable.

4 Install software prerequisites

You will need the following software:

git
GNU Make
RISC-V GNU Toolchain
RISC-V OpenOCD
ESP-IDF from Espressif

Binary RISC-V GNU Toolchain and OpenOCD are available from SiFive at https://github.com/sifive/freedom-tools/releases

Download and unpack the archives for your platform and export RISCV_PATH and RISCV_OPENOCD_PATH variables:


export RISCV_PATH=/path/to/riscv64-gcc
export RISCV_OPENOCD_PATH=/path/to/riscv-openocd

To install ESP-IDF follow instructions from ESP-IDF Programming Guide. Install version 4.2 or later.

5 Obtain source

git repository can be cloned by running the following command:


git clone https://git.majstor.org/mikroPhone

Repository contains following directories:

hw/mikroPhone: KiCad project that contains main board schematics and layout
hw/display: KiCad project that contains display adapter board schematics and layout
hw/prog: KiCad project that contains FT2232H-56Q adapter board schematics and layout
fw/fe310: Firmware for Freedom E310 SoC
fw/esp32: Firmware for Espressif ESP32 SoC
ecp: EllipticCP implementation

6 Compile and upload firmware

To build firmware for FE310 run follwing commands:


cd <path to repository>/fw/fe310
make
cd phone
make upload_ftdi

To build firmware for ESP32 run following commands:


cd <path to repository>/fw/esp32
make menuconfig
make
make flash

In make menuconfig, please make sure that Enable PPP support is selected under Component config -> LWIP menu and that Notify Phase Callback, PAP Support and CHAP Support are selected under PPP menu.

Before flashing ESP32 device you must put it into programming mode:

press and hold WAKE button (SW2 - on the left side of the board)
push ESP32 reset switch (SW201 - bottom right)