MAX6955 LED driver

Files at this revision

API Documentation at this revision

Comitter:
Kentaro Okuda
Date:
Sat Aug 11 15:27:43 2018 -0400
Parent:
2:f6c4ed9cbf0e
Commit message:
refactoring. extract a method to generate printable char.

Changed in this revision

MAX6955.cpp Show annotated file Show diff for this revision Revisions of this file
diff -r f6c4ed9cbf0e -r fbcb79f6e0a8 MAX6955.cpp
--- a/MAX6955.cpp	Sat Aug 11 10:56:18 2018 -0400
+++ b/MAX6955.cpp	Sat Aug 11 15:27:43 2018 -0400
@@ -6,14 +6,20 @@
 
 MAX6955::MAX6955(PinName sda, PinName scl, char driver): i2c_(sda, scl), driver_(driver){}
 
-static void prepareString(char* buffer, char* i2cData) {
+static char getPrintableChar(char c) {
+    if (c < 32 || c > 126) { // make sure its printable
+        return 32; // if not, replace it with "space"
+    }
+    return c;
+}
+
+static char* getString(char* buffer) {
+    static char i2cData[9];
+    i2cData[0] = 0x20; // first digit
     for (int i = 0; i < 8; i++) {
-        if (buffer[i] < 32 || buffer[i] > 126) { // make sure its printable
-            i2cData[i+1] = 32; // if not, replace it with "space"
-        } else {
-            i2cData[i+1] = buffer[i];
-        }
+        i2cData[i+1] = getPrintableChar(buffer[i]);
     }
+    return i2cData;
 }
 
 int MAX6955::write(char command, char data) {
@@ -26,10 +32,9 @@
 }
 
 int MAX6955::writeS(char* buffer) {
-    char i2cData[9];
-    i2cData[0] = 0x20; // first digit
-    prepareString(buffer, i2cData);
-    int result = i2c_.write(driver_, (char *) i2cData, 9);
+    char* i2cData;
+    i2cData = getString(buffer);
+    int result = i2c_.write(driver_, i2cData, 9);
     wait(0.07);
     return result;
 }