Has anyone found a reliable way to adjust the SPI clock speed on the Uno R4 Wifi and/or Giga R1 Wifi? I've been using the Adafruit HX8357 touchscreen and have boiled my problems with it down to SPI clock speed. It works great with the Uno R3 which runs at 8MHz, but does not work with either the R4 (24MHz) or the Giga R1 (125MHz). Hooked it up to my O-Scope and it's showing the correct rated speeds, but I'd like to slow the two faster ones down to 8MHz. So far I've just used the graphics test example provided in the library trying to tweak SPI settings through the SPI.beginTransaction() function with no luck. It compiles and uploads just fine, but doesn't actually change the SPI clock speed. Code is shown below:
/***************************************************
This is our library for the Adafruit HX8357D Breakout
----> http://www.adafruit.com/products/2050
Check out the links above for our tutorials and wiring diagrams
These displays use SPI to communicate, 4 or 5 pins are required to
interface (RST is optional)
Adafruit invests time and resources providing this open source code,
please support Adafruit and open-source hardware by purchasing
products from Adafruit!
Written by Limor Fried/Ladyada for Adafruit Industries.
MIT license, all text above must be included in any redistribution
****************************************************/
#include <SPI.h>
#include "Adafruit_GFX.h"
#include "Adafruit_HX8357.h"
// These are 'flexible' lines that can be changed
#define TFT_CS 10
#define TFT_DC 9
#define TFT_RST 8 // RST can be set to -1 if you tie it to Arduino's reset
// Use hardware SPI (on Uno, #13, #12, #11) and the above for CS/DC
Adafruit_HX8357 tft = Adafruit_HX8357(TFT_CS, TFT_DC, TFT_RST);
// SoftSPI - note that on some processors this might be *faster* than hardware SPI!
// Adafruit_HX8357 tft = Adafruit_HX8357(TFT_CS, TFT_DC, MOSI, SCK, TFT_RST, MISO);
SPISettings screen_setting(8000000, MSBFIRST, SPI_MODE3);
void setup() {
SPI.begin();
SPI.beginTransaction(screen_setting);
Serial.begin(9600);
Serial.println("HX8357D Test!");
tft.begin();
// read diagnostics (optional but can help debug problems)
uint8_t x = tft.readcommand8(HX8357_RDPOWMODE);
Serial.print("Display Power Mode: 0x"); Serial.println(x, HEX);
x = tft.readcommand8(HX8357_RDMADCTL);
Serial.print("MADCTL Mode: 0x"); Serial.println(x, HEX);
x = tft.readcommand8(HX8357_RDCOLMOD);
Serial.print("Pixel Format: 0x"); Serial.println(x, HEX);
x = tft.readcommand8(HX8357_RDDIM);
Serial.print("Image Format: 0x"); Serial.println(x, HEX);
x = tft.readcommand8(HX8357_RDDSDR);
Serial.print("Self Diagnostic: 0x"); Serial.println(x, HEX);
Serial.println(F("Benchmark Time (microseconds)"));
tft.setRotation(1);
Serial.print(F("Text "));
Serial.println(testText());
delay(500);
Serial.print(F("Lines "));
Serial.println(testLines(HX8357_CYAN));
delay(500);
Serial.print(F("Rectangles (outline) "));
Serial.println(testRects(HX8357_GREEN));
delay(500);
tft.fillScreen(HX8357_BLACK);
Serial.print(F("Circles (outline) "));
Serial.println(testCircles(10, HX8357_RED));
delay(500);
Serial.print(F("Triangles (outline) "));
Serial.println(testTriangles());
delay(500);
Serial.print(F("Triangles (filled) "));
Serial.println(testFilledTriangles());
delay(500);
Serial.print(F("Rounded rects (outline) "));
Serial.println(testRoundRects());
delay(500);
Serial.print(F("Rounded rects (filled) "));
Serial.println(testFilledRoundRects());
delay(500);
Serial.println(F("Done!"));
}
void loop(void) {
for(uint8_t rotation=0; rotation<4; rotation++) {
tft.setRotation(rotation);
testText();
delay(1000);
}
}
unsigned long testFillScreen() {
unsigned long start = micros();
tft.fillScreen(HX8357_RED);
tft.fillScreen(HX8357_GREEN);
tft.fillScreen(HX8357_BLUE);
tft.fillScreen(HX8357_WHITE);
return micros() - start;
}
unsigned long testText() {
tft.fillScreen(HX8357_BLACK);
unsigned long start = micros();
tft.setCursor(0, 0);
tft.setTextColor(HX8357_WHITE); tft.setTextSize(1);
tft.println("Hello World!");
tft.setTextColor(HX8357_YELLOW); tft.setTextSize(2);
tft.println(1234.56);
tft.setTextColor(HX8357_RED); tft.setTextSize(3);
tft.println(0xDEADBEEF, HEX);
tft.println();
tft.setTextColor(HX8357_GREEN);
tft.setTextSize(5);
tft.println("Groop");
tft.setTextSize(2);
tft.println("I implore thee,");
tft.setTextSize(1);
tft.println("my foonting turlingdromes.");
tft.println("And hooptiously drangle me");
tft.println("with crinkly bindlewurdles,");
tft.println("Or I will rend thee");
tft.println("in the gobberwarts");
tft.println("with my blurglecruncheon,");
tft.println("see if I don't!");
tft.setTextColor(HX8357_WHITE);
tft.println(F("Alice was beginning to get very tired of sitting by her sister on the bank, and of having nothing to do: once or twice she had peeped into the book her sister was reading, but it had no pictures or conversations in it, 'and what is the use of a book,' thought Alice 'without pictures or conversations?'"));
tft.println(F("So she was considering in her own mind (as well as she could, for the hot day made her feel very sleepy and stupid), whether the pleasure of making a daisy-chain would be worth the trouble of getting up and picking the daisies, when suddenly a White Rabbit with pink eyes ran close by her."));
tft.println(F("There was nothing so very remarkable in that; nor did Alice think it so very much out of the way to hear the Rabbit say to itself, 'Oh dear! Oh dear! I shall be late!' (when she thought it over afterwards, it occurred to her that she ought to have wondered at this, but at the time it all seemed quite natural); but when the Rabbit actually took a watch out of its waistcoat-pocket, and looked at it, and then hurried on, Alice started to her feet, for it flashed across her mind that she had never before seen a rabbit with either a waistcoat-pocket, or a watch to take out of it, and burning with curiosity, she ran across the field after it, and fortunately was just in time to see it pop down a large rabbit-hole under the hedge."));
tft.println(F("In another moment down went Alice after it, never once considering how in the world she was to get out again."));
tft.println(F("The rabbit-hole went straight on like a tunnel for some way, and then dipped suddenly down, so suddenly that Alice had not a moment to think about stopping herself before she found herself falling down a very deep well."));
tft.println(F("Either the well was very deep, or she fell very slowly, for she had plenty of time as she went down to look about her and to wonder what was going to happen next. First, she tried to look down and make out what she was coming to, but it was too dark to see anything; then she looked at the sides of the well, and noticed that they were filled with cupboards and book-shelves; here and there she saw maps and pictures hung upon pegs. She took down a jar from one of the shelves as she passed; it was labelled 'ORANGE MARMALADE', but to her great disappointment it was empty: she did not like to drop the jar for fear of killing somebody, so managed to put it into one of the cupboards as she fell past it."));
return micros() - start;
}
unsigned long testLines(uint16_t color) {
unsigned long start;
int x1, y1, x2, y2,
w = tft.width(),
h = tft.height();
tft.fillScreen(HX8357_BLACK);
x1 = y1 = 0;
y2 = h - 1;
start = micros();
for(x2=0; x2<w; x2+=6) tft.drawLine(x1, y1, x2, y2, color);
x2 = w - 1;
for(y2=0; y2<h; y2+=6) tft.drawLine(x1, y1, x2, y2, color);
return micros() - start;
}
unsigned long testFastLines(uint16_t color1, uint16_t color2) {
unsigned long start;
int x, y, w = tft.width(), h = tft.height();
tft.fillScreen(HX8357_BLACK);
start = micros();
for(y=0; y<h; y+=5) tft.drawFastHLine(0, y, w, color1);
for(x=0; x<w; x+=5) tft.drawFastVLine(x, 0, h, color2);
return micros() - start;
}
unsigned long testRects(uint16_t color) {
unsigned long start;
int n, i, i2,
cx = tft.width() / 2,
cy = tft.height() / 2;
tft.fillScreen(HX8357_BLACK);
n = min(tft.width(), tft.height());
start = micros();
for(i=2; i<n; i+=6) {
i2 = i / 2;
tft.drawRect(cx-i2, cy-i2, i, i, color);
}
return micros() - start;
}
unsigned long testFilledRects(uint16_t color1, uint16_t color2) {
unsigned long start, t = 0;
int n, i, i2,
cx = tft.width() / 2 - 1,
cy = tft.height() / 2 - 1;
tft.fillScreen(HX8357_BLACK);
n = min(tft.width(), tft.height());
for(i=n; i>0; i-=6) {
i2 = i / 2;
start = micros();
tft.fillRect(cx-i2, cy-i2, i, i, color1);
t += micros() - start;
// Outlines are not included in timing results
tft.drawRect(cx-i2, cy-i2, i, i, color2);
}
return t;
}
unsigned long testFilledCircles(uint8_t radius, uint16_t color) {
unsigned long start;
int x, y, w = tft.width(), h = tft.height(), r2 = radius * 2;
tft.fillScreen(HX8357_BLACK);
start = micros();
for(x=radius; x<w; x+=r2) {
for(y=radius; y<h; y+=r2) {
tft.fillCircle(x, y, radius, color);
}
}
return micros() - start;
}
unsigned long testCircles(uint8_t radius, uint16_t color) {
unsigned long start;
int x, y, r2 = radius * 2,
w = tft.width() + radius,
h = tft.height() + radius;
// Screen is not cleared for this one -- this is
// intentional and does not affect the reported time.
start = micros();
for(x=0; x<w; x+=r2) {
for(y=0; y<h; y+=r2) {
tft.drawCircle(x, y, radius, color);
}
}
return micros() - start;
}
unsigned long testTriangles() {
unsigned long start;
int n, i, cx = tft.width() / 2 - 1,
cy = tft.height() / 2 - 1;
tft.fillScreen(HX8357_BLACK);
n = min(cx, cy);
start = micros();
for(i=0; i<n; i+=5) {
tft.drawTriangle(
cx , cy - i, // peak
cx - i, cy + i, // bottom left
cx + i, cy + i, // bottom right
tft.color565(200, 20, i));
}
return micros() - start;
}
unsigned long testFilledTriangles() {
unsigned long start, t = 0;
int i, cx = tft.width() / 2 - 1,
cy = tft.height() / 2 - 1;
tft.fillScreen(HX8357_BLACK);
start = micros();
for(i=min(cx,cy); i>10; i-=5) {
start = micros();
tft.fillTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i,
tft.color565(0, i, i));
t += micros() - start;
tft.drawTriangle(cx, cy - i, cx - i, cy + i, cx + i, cy + i,
tft.color565(i, i, 0));
}
return t;
}
unsigned long testRoundRects() {
unsigned long start;
int w, i, i2,
cx = tft.width() / 2 ,
cy = tft.height() / 2 ;
tft.fillScreen(HX8357_BLACK);
w = min(tft.width(), tft.height());
start = micros();
for(i=0; i<w; i+=8) {
i2 = i / 2 - 2;
tft.drawRoundRect(cx-i2, cy-i2, i, i, i/8, tft.color565(i, 100, 100));
}
return micros() - start;
}
unsigned long testFilledRoundRects() {
unsigned long start;
int i, i2,
cx = tft.width() / 2 + 10,
cy = tft.height() / 2 + 10;
tft.fillScreen(HX8357_BLACK);
start = micros();
for(i=min(tft.width(), tft.height()) - 20; i>25; i-=6) {
i2 = i / 2;
tft.fillRoundRect(cx-i2, cy-i2, i-20, i-20, i/8, tft.color565(100, i/2, 100));
}
return micros() - start;
}
I have tried SPI.beginTransaction() in the loop function as well to no avail. Have also tried using the different SPI modes (SPI_MODE0-3). I'm inclined to believe that the clock speed is the issue since it works with Software SPI which runs at 350kHz, but not at the native 24MHz for hardware SPI. If anyone has any other suggestions, I'm open to anything.
Thanks in advance!