fix for compiling error

MemoryLCD.h

@@ -7,8 +7,9 @@
 #include <iostream>
 
 // Memory LCD pixel dimensions - ALTER ACCORDING TO YOUR PARTICULAR LCD MODEL
-#define LCDWIDTH		(96)
-#define LCDHEIGHT		(96)
+// remark: (400x270) for sharp lcd 2.7 mono memory LCD (ls027bdh01)
+#define LCDWIDTH		(400)
+#define LCDHEIGHT		(240)
 
 // Delay constants for LCD timing   // (Datasheet values)
 #define PWRUP_DISP_DELAY	40  // (>30us)

README.md

@@ -0,0 +1,37 @@
+# SHARP 2.7" 400x240px memory LCD on Raspberry Pi
+
+This repository was forked from: [MakerDyne/Memory-LCD-for-Raspberry-Pi](https://github.com/MakerDyne/Memory-LCD-for-Raspberry-Pi)
+
+Modified for resolving compiling error from the original version of demo code, aim to validate the application of SHARP 400x270 mono memory LCD running on RaspberryPi, and keep in record for personal refrence.
+
+![entire_running_setup](images/entire_running_setup.jpg)
+
+
+
+## Hardware Setup
+Raspberry Pi 4
+
+Adafruit SHARP Memory Display Breakout - 2.7" 400x240 Monochrome (LS027B7DH01)
+
+wiring:
+refer to [RPi Low-level peripherals](https://elinux.org/RPi_Low-level_peripherals#General_Purpose_Input.2FOutput_.28GPIO.29)
+| LCD PIN    | Rpi4 GPIO Name  | Rpi4 PIN#             | changeable? | remark  |
+|------------|----------------|----------------------|-------------|---|
+| 3v3        | Any [3.3v] PIN | 1/21                 |             |   |
+| Gnd        | Any [GND] PIN  | 6/9/14/2025/30/34/39 |             |   |
+| CLK(SCLK)  | GPIO11(SCLK)   | 23                   |             |   |
+| DI(MOSI)   | GPIO10(MOSI)   | 19                   |             |   |
+| CS(SS)     | GPIO23         | 16                   |             |   |
+| EMD(EXTMD) |                |                      |             | no need for Adafruit module  |
+| DISP       | GPIO24         | 18                   | ::check::   | no need for Adafruit module  |
+| EIN(EXTIN) | GPIO25         | 22                   | ::check::   | no need for Adafruit module  |
+
+![rpi4-pin-img](https://elinux.org/images/thumb/3/30/B_plus_hdr_sm.jpg/300px-B_plus_hdr_sm.jpg)
+![rpi4-pin-sch](https://elinux.org/images/thumb/5/5c/Pi-GPIO-header.png/300px-Pi-GPIO-header.png)
+
+
+## Compile from source code
+``
+
+
+last update: Dec. 9, 2021, KW.

examples/demo/demo.cpp

@@ -65,7 +65,7 @@ int main() {
       for(unsigned int radius = 5; radius < expandingCircleRadius; radius++) {
 	for(unsigned int y = originY - radius; y <= originY; y++) {
 	  // need to calculate left and right limits of the circle
-	  float theta = acos(float(abs(originY-y))/float(radius));
+	  float theta = acos(float(abs(int(originY-y)))/float(radius));
 	  theta -= 1.5708;
 	  unsigned int xLength = cos(theta)*float(radius);
 	  for(unsigned int x = originX - xLength; x <= originX; x++) {
@@ -81,7 +81,7 @@ int main() {
       for(unsigned int radius = expandingCircleRadius; radius > 2; radius--) {
 	for(unsigned int y = originY - radius; y <= originY; y++) {
 	  // need to calculate left and right limits of the circle
-	  float theta = acos(float(abs(originY-y))/float(radius));
+	  float theta = acos(float(abs(int(originY-y)))/float(radius));
 	  theta -= 1.5708;
 	  unsigned int xLength = cos(theta)*float(radius);
 	  for(unsigned int x = originX - xLength; x <= originX ; x++) {
@@ -114,7 +114,7 @@ int main() {
       // draw circle about the centre
       for(unsigned int y = circleOriginY - circleRadius; y <= circleOriginY; y++) {
 	// need to calculate left and right limits of the circle
-	float theta = acos(float(std::abs(circleOriginY-y))/float(circleRadius));
+	float theta = acos(float(std::abs(int(circleOriginY-y)))/float(circleRadius));
 	theta -= 1.5708;
 	unsigned int xLength = cos(theta)*float(circleRadius);
 	for(unsigned int x = circleOriginX - xLength; x <= circleOriginX; x++) {