From 9e34cd9dffbf8df6c42f6af8f843fbd38b23dafc Mon Sep 17 00:00:00 2001
From: Florian Agbuya <fa@m-labs.ph>
Date: Thu, 22 Aug 2024 16:27:15 +0800
Subject: [PATCH] add both channels in loopback

---
 fast-servo/pyfastservo/loopback.py | 62 ++++++++++++++++++------------
 1 file changed, 37 insertions(+), 25 deletions(-)

diff --git a/fast-servo/pyfastservo/loopback.py b/fast-servo/pyfastservo/loopback.py
index 13ee77b..52b14b7 100644
--- a/fast-servo/pyfastservo/loopback.py
+++ b/fast-servo/pyfastservo/loopback.py
@@ -1,47 +1,59 @@
 import time
 from pyfastservo import adc, dac
 from pyfastservo.common import (
-    ADC_CH1_HIGH_ADDR,
-    ADC_CH1_LOW_ADDR,
-    CH1_HIGH_WORD_ADDR,
-    CH1_LOW_WORD_ADDR,
-    read_from_memory,
-    write_to_memory
+    ADC_CH0_HIGH_ADDR, ADC_CH0_LOW_ADDR,
+    ADC_CH1_HIGH_ADDR, ADC_CH1_LOW_ADDR,
+    CH0_HIGH_WORD_ADDR, CH0_LOW_WORD_ADDR,
+    CH1_HIGH_WORD_ADDR, CH1_LOW_WORD_ADDR,
+    read_from_memory, write_to_memory
 )
 
-def read_adc():
-    adc_value = adc.read_adc_channel(ADC_CH1_HIGH_ADDR, ADC_CH1_LOW_ADDR)
-    return adc_value
+def read_adc(channel):
+    if channel == 0:
+        return adc.read_adc_channel(ADC_CH0_HIGH_ADDR, ADC_CH0_LOW_ADDR)
+    elif channel == 1:
+        return adc.read_adc_channel(ADC_CH1_HIGH_ADDR, ADC_CH1_LOW_ADDR)
+    else:
+        raise ValueError("Invalid ADC channel")
 
 def write_dac(value):
     dac.set_dac_output(value)
 
-def read_dac():
-    high_word = read_from_memory(CH1_HIGH_WORD_ADDR, 1)[0]
-    low_word = read_from_memory(CH1_LOW_WORD_ADDR, 1)[0]
+def read_dac(channel):
+    if channel == 0:
+        high_word = read_from_memory(CH0_HIGH_WORD_ADDR, 1)[0]
+        low_word = read_from_memory(CH0_LOW_WORD_ADDR, 1)[0]
+    elif channel == 1:
+        high_word = read_from_memory(CH1_HIGH_WORD_ADDR, 1)[0]
+        low_word = read_from_memory(CH1_LOW_WORD_ADDR, 1)[0]
+    else:
+        raise ValueError("Invalid DAC channel")
     return (high_word << 8) | low_word
 
 def perform_loopback_test(test_value):
-    print(f"Setting DAC output to {test_value}...")
+    print(f"\nSetting DAC output to {test_value}...")
     write_dac(test_value)
     time.sleep(0.1)  # Allow time for the signal to stabilize
 
-    print("Reading ADC value...")
-    adc_value = read_adc()
-    print(f"ADC readback: {adc_value}")
+    for channel in [0, 1]:
+        print(f"\nTesting Channel {channel}")
+        
+        print(f"Reading ADC CH{channel} value...")
+        adc_value = read_adc(channel)
+        print(f"ADC CH{channel} readback: {adc_value}")
 
-    print("Reading DAC value...")
-    dac_value = read_dac()
-    print(f"DAC readback: {dac_value}")
+        print(f"Reading DAC CH{channel} value...")
+        dac_value = read_dac(channel)
+        print(f"DAC CH{channel} readback: {dac_value}")
 
-    if abs(test_value - adc_value) <= 2 and abs(test_value - dac_value) <= 2:
-        print("Loopback test PASSED!")
-    else:
-        print("Loopback test FAILED!")
-        print(f"Expected: {test_value}, ADC: {adc_value}, DAC: {dac_value}")
+        if abs(test_value - adc_value) <= 2 and abs(test_value - dac_value) <= 2:
+            print(f"Loopback test for Channel {channel} PASSED!")
+        else:
+            print(f"Loopback test for Channel {channel} FAILED!")
+            print(f"Expected: {test_value}, ADC: {adc_value}, DAC: {dac_value}")
 
 def main():
-    test_value = 0x2000  # Mid-range value (8192 in decimal)
+    test_value = 0x0FFF  # Mid-range value (4095 in decimal)
     perform_loopback_test(test_value)
 
 if __name__ == "__main__":