From eafad7ccdbb527a30a959e4c2142886a24219ce3 Mon Sep 17 00:00:00 2001
From: Konstantin Lampalzer <konstantin@localhost.systems>
Date: Thu, 14 Oct 2021 13:36:03 +0200
Subject: [PATCH] Add local development to SPI

---
 compLib/Spi.py | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/compLib/Spi.py b/compLib/Spi.py
index a3b2c14..5f7d964 100644
--- a/compLib/Spi.py
+++ b/compLib/Spi.py
@@ -1,4 +1,4 @@
-import spidev
+import importlib
 from threading import Thread, Lock
 from enum import IntEnum
 import time
@@ -12,13 +12,17 @@ SPI_SPEED = 1000000
 SPI_BUFFER_SIZE = 32
 SPI_HEALTH = True
 
-spi = spidev.SpiDev()
-spi.open(SPI_BUS, SPI_DEVICE)
-spi.max_speed_hz = SPI_SPEED
-spi.mode = 0
-spi.bits_per_word = 8
+# For development purposes
+spi_found = importlib.util.find_spec("spidev") is not None
+spi =  None
+if spi_found:
+    spi = spidev.SpiDev()
+    spi.open(SPI_BUS, SPI_DEVICE)
+    spi.max_speed_hz = SPI_SPEED
+    spi.mode = 0
+    spi.bits_per_word = 8
 
-spi_mutex = Lock()
+    spi_mutex = Lock()
 
 class Register(IntEnum):
     IDENTIFICATION_MODEL_ID = 1,
@@ -106,6 +110,9 @@ class Spi(object):
 
     @staticmethod
     def transfer(tx_buffer: list):
+        if not spi_found:
+            return [] * SPI_BUFFER_SIZE
+        
         write_reg = tx_buffer[1]
 
         spi.xfer(tx_buffer)