Grove E-Ink on Raspberry Pi

I am having difficulty getting a response from a e-paper screen (Grove - Triple Color E-Ink Display 2.13” - sku 104020130).

I have it connected to a grove base hat (sku 103030275) on a raspberry pi 4b on the UART labeled Grove connector. The wiki suggests there is a raspberry pi guide coming soon and there is a STM32 firmware but does not give any links. From the arduino C# demo I’ve tried to recreate the functions using nodeJS and the serialport library but get no response.

I have a baud rate of 230400 and listen for a ‘c’ before sending a ‘a’ then wait for a ‘b’ before sending a byte array for the content.

‘’’
function setup_display() {
var dispPort = new SerialPort(’/dev/ttyAMA0’, { baudRate: 230400 })
return new Promise((resolve, reject) => {
dispPort.open(() => {
console.log(‘Port opened.’)
dispPort.on(‘data’, function (chunk) {
console.log(chunk)
if (chunk == ‘c’)
dispPort.write(‘a’)
if (chunk == ‘b’)
resolve(dispPort)
})
dispPort.on(‘error’, function (err) {
console.error('Caught Error: ', err)
reject(err)
})
})
})
}

setup_display().then(com => {
console.log(‘Ready for data.’)
for (let i = 0; i < 2756; i++) { // write white screen
com.write(0xFF)
}
})
‘’’

I am under the impression I must have the UART port wrong or it requires setup? Currently using ‘ttyAMA0’. Some guidance would be much appreciated.

Hi, MDF96
I am sorry that I am not familiar with nodeJS. In my experience, I suggest you use a oscilloscope or a logic analyzer to get the wave form of your port. It might help you to locate problem.