stepansnigirev / esp32_upy_bitcoin

esp32_upy_bitcoin

Installation

Download submodules:

git submodule update --init --recursive

Cross-compile micropython

cd micropython/mpy-cross
make
cd ../..

Also added 2 lines in micropython/ports/esp32/mpconfigport.h:

#define MODULE_HASHLIB_ENABLED      (1)
#define MODULE_ECC_ENABLED          (1)

Copy over the micropython files:

cp -r libs/* micropython/ports/esp32/modules/

Compile firmware:

ESPIDF=~/esp/esp-idf make USER_C_MODULES=../../../usermods

Upload firmware

esptool.py --chip esp32 --port <port> --baud 460800 erase_flash
esptool.py --chip esp32 --port <port> --baud 460800 write_flash -z 0x1000 build/firmware.bin

Then we have two new modules:

• bitcoin.ecc containing ecc primitives
• hashlib with all hash functions

$ screen /dev/ttyUSB0 115200
>>> import bitcoin
>>> dir(bitcoin)
['__class__', '__name__', '__path__', 'helper', 'PrivateKey', 'PublicKey', 'ecc']
>>> dir(bitcoin.ecc)
['__class__', '__name__', 'BytesIO', '_ecc', 'hashlib', 'hexlify', 'hash160', 'encode_base58_checksum', 'decode_base58', 'p2pkh_script', 'hmac', 'N', 'FieldElement', 'PrivateKey', 'PublicKey', 'G']
>>> import hashlib
>>> dir(hashlib)
['__class__', '__name__', 'ripemd160', 'sha1', 'sha256', 'sha512']

Example - show Bitcoin address on m5stack screen

import m5stack
from m5stack import LCD, fonts, color565
from bitcoin import PrivateKey

lcd = LCD()
lcd.set_font(fonts.tt24)
lcd.set_color(color565(0,50,250), color565(255,255,255)) # text color, background color
lcd.erase()

pk = PrivateKey.parse("Kyo7UhSKAXDSddUWE7FmUiTfZnvgmyVcapjUyPkhKxHF6ZXD7n2T")
# pk = PrivateKey(0x473628abb8917391, compressed=True, testnet=True)
lcd.set_pos(50,50)
lcd.print(pk.address())

Example - show list of files on the SD card

from m5stack import LCD, fonts, color565
from m5stack import SDCard
import os

lcd = LCD()
lcd.set_font(fonts.tt24)
lcd.set_color(color565(0,50,250), color565(255,255,255)) # text color, background color
lcd.erase()

sd = SDCard()
os.mount(sd, '/sd')
files = os.listdir('/sd')
for file in files:
	lcd.print(file)
os.umount('/sd')

Reference

• Useful doc for user modules