Replay I2C

We highly encourage everyone to use our new Python package which is packed with features. This library is still supported, but is not recommended for new design.

The following script can be used to repeat I2C transactions captured and exported from Saleae Logic. After the capture is completed, export the I2C analyzer results as a csv file. You can follow this guide to export the file. The exported data should be in HEX-- Note that the base/radix of the exported data will match the current setting for display in the software.

Simply modify the parameters in lines 9-15 in the script below and then everything is ready to play back the file from the Binho Nova Multi-Protocol USB Host Adapter.

For easy testing, here's an example export file from Saleae Logic that works with this script:

9KB

i2c_eeprom.csv

Open

from binhoHostAdapter import binhoHostAdapter
from binhoHostAdapter import binhoUtilities

from datetime import datetime, timedelta, time
import math
import csv


i2cIndex = 0
i2cClockFreq = 400000
i2cPullEn = 'EN'

captureExportFile = 'C:\\Users\\Batman\\Desktop\\LogicExports\\i2c_eeprom.csv'

binhoCommPort = 'COM27'


# ---- No Need to Change Anything Below Here ----

print("Opening " + binhoCommPort + "...")
print()

# create the binhoHostAdapter object
binho = binhoHostAdapter.binhoHostAdapter(binhoCommPort)

print("Connecting to binho host adapter...")
print()

print("Connected!")
print()
binho.setLEDColor('YELLOW')

print("Setting I2C bus parameters:")
print()
binho.setOperationMode(0, 'I2C')

print('Clock Frequency: ' + str(i2cClockFreq))
binho.setClockI2C(i2cIndex, i2cClockFreq)

print('PullUps: ' + str(i2cPullEn))
binho.setPullUpStateI2C(i2cIndex, i2cPullEn)

print()
print("Computing USB Transit time...")
t0 = datetime.now()
binho.ping()
binho.ping()
binho.ping()
binho.ping()
binho.ping()
t1 = datetime.now()

avgUSBTxTime = (t1 - t0)/5
print('Average USB Tx Time = ' + str(avgUSBTxTime) + 's')
print()


print("Beginning Replay...")
print()

with open(captureExportFile) as captureExport:
	capture_reader = csv.reader(captureExport, delimiter=',')
	rowCount = 0

	startTime = datetime.now()
	prevTimestamp = startTime
	prevRowTime = 0

	currentPacketID = 0
	deviceAddress = 0
	payload = []
	isReadPacket = True
	
	for row in capture_reader:

		if rowCount == 0:

			# These are the column headers, just advance to the next row
			rowCount += 1
			print('PacketID#\tTimestamp\t\t\tAddress\tType\tLen(Bytes)')

		else:
			rowPacketID = row[1]

			#check if packetID is empty
			if rowPacketID == "":
				#this is a single write command with no data to follow it, skip it
				rowCount +=1

			elif int(row[1]) == currentPacketID:
				currRowTime = float(row[0])
				deviceAddress = int(row[2],16)
				payload.append(int(row[3], 16))

				if row[4] == 'Write':
					isReadPacket = False
				else:
					isReadPacket = True

				rowCount += 1

			else:
				# starts a new packet, so do the transaction we loaded

				deltaTimems = (currRowTime - prevRowTime) * 1000
				#deltaTimems = 0.125 * 1000
				#print('DeltaT: ' + str(deltaTimems))
				print('Waiting ' + str(timedelta(0,0,0,math.floor(deltaTimems))) + ' until next packet transmission', end='\r')

				while (datetime.now() - prevTimestamp) < timedelta(0,0,0,math.floor(deltaTimems)):
					#nothing, sleep does not have high enough resolution
					#print('WAITING ' + str(datetime.now() - prevTimestamp))
					pass

				if isReadPacket:

					print(str(currentPacketID) + '\t\t' + str(datetime.now()) + '\t' +  format(deviceAddress, '#02x') + '\tREAD\t' + str(len(payload)))

					binho.readBytesI2C(i2cIndex, deviceAddress, len(payload))

				else:

					print(str(currentPacketID) + '\t\t' + str(datetime.now()) + '\t' + format(deviceAddress, '#02x') + '\tWRITE\t' + str(len(payload)))
					binho.startI2C(i2cIndex, deviceAddress)

					for dataByte in payload:
						binho.writeByteI2C(i2cIndex, dataByte)

					binho.endI2C(i2cIndex)

				payload = []
				prevTimestamp = datetime.now()
				prevRowTime = currRowTime

				currentPacketID = int(row[1])
				currRowTime = float(row[0])

				deviceAddress = int(row[2],16)
				payload.append(int(row[3], 16))

				if row[4] == 'Write':
					isReadPacket = False
				else:
					isReadPacket = True

				rowCount += 1

print('Finished Replaying...')
print()
binho.setLEDColor('BLUE')
binho.close()
print('Goodbye!')