1 files changed, 66 insertions, 0 deletions
diff --git a/usv_driver.py b/usv_driver.py
new file mode 100755
index 0000000..c8ba8bc
--- /dev/null
+++ b/usv_driver.py
@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+
+import serial
+import json
+import re
+
+class Usv(object):
+    def __init__(self, device, baudrate, json_file):
+        self._serial_port = serial.Serial(device,
+                baudrate=baudrate)
+
+        # force a clean prompt
+        self._serial_port.write(b"\r")
+        self._read_until_prompt()
+        #print("cleaned prompt")
+        with open(json_file) as fhandle:
+            self.json_params = json.load(fhandle)
+
+
+    def _read_until_prompt(self):
+        # match on "\n=>"
+        prompt = False
+        inbuf = []
+        while not prompt:
+            inbuf.append(self._serial_port.read(1))
+            if len(inbuf) > 2:
+                if inbuf[-3] == b"\n" and \
+                        inbuf[-2] == b"=" and inbuf[-1] == b">":
+                    prompt = True
+        return inbuf
+    
+    def get_parameters(self):
+        # [{'name': 'acvoltsin', 'index': 1}, 
+        results = {}
+
+        for parameter in self.json_params:
+            outbuf = "d %s\r" % parameter['num']
+            self._serial_port.write(outbuf.encode())
+            inbuf = self._read_until_prompt()
+            
+            sbuf = ""
+            for char in inbuf:
+                sbuf += char.decode("utf-8")
+            #print("-->%s<--" % sbuf)
+
+            regex = parameter['regex']
+            match = re.search(regex, sbuf, re.MULTILINE)
+            
+            if match:
+                name = parameter['name']
+                value = float(match.group(1))
+
+                results.setdefault(name, value)
+                #print("MATCH: %s: %f" % (name,value))
+
+        return results
+          
+
+
+if __name__ == "__main__":
+    import pprint
+
+    usv = Usv("/dev/ttyU0", 600, "usv_param.json")
+    parameters = usv.get_parameters()
+    pprint.pprint(parameters)
+