worked on SPI, fixed some bugs

adjusted LCD code
added code for INA3221
worked on UI

io/HardSPI.h

@@ -51,7 +51,7 @@ private:
 		buscfg.sclk_io_num = PIN_NUM_CLK;
 		buscfg.quadwp_io_num = -1;
 		buscfg.quadhd_io_num = -1;
-		buscfg.max_transfer_sz = MAX_LEN;//320*240*2;
+		buscfg.max_transfer_sz = MAX_LEN;
 		buscfg.flags = 0;
 		buscfg.intr_flags = 0;
 
@@ -80,9 +80,12 @@ public:
 	void write(const uint8_t* data, size_t len) {
 
 		spi_transaction_t t;
-		memset(&t, 0, sizeof(spi_transaction_t));
 
 		while(len > 0) {
+			
+			// ensure the transaction is reset to defaults.
+			// this is mandatory! as the ESP adjusts some parameters while/after sending!
+			memset(&t, 0, sizeof(spi_transaction_t));
 
 			const size_t chunkLen = min(MAX_LEN, (len));
 			t.length = 8 * chunkLen;		// in bits
@@ -136,6 +139,23 @@ public:
 
 	}
 
+	/** send 4 bytes onto the bus while reading 4 bytes response */
+	uint8_t readWriteByte(uint8_t write) {
+
+		spi_transaction_t t;
+		memset(&t, 0, sizeof(spi_transaction_t));
+		t.length = 8*1;
+		t.rxlength = 8*1;
+		t.tx_data[0] = (write >>  0) & 0xFF;
+		t.flags = SPI_TRANS_USE_RXDATA | SPI_TRANS_USE_TXDATA;
+
+		esp_err_t ret = spi_device_polling_transmit(spi, &t);
+		ESP_ERROR_CHECK(ret);
+
+		return (static_cast<uint32_t>(t.rx_data[0]));
+		
+	}
+
 	/** send 4 bytes onto the bus while reading 4 bytes response */
 	uint32_t readWriteQuad(uint32_t write) {
 
@@ -220,6 +240,10 @@ public:
 		ESP_ERROR_CHECK(ret);
 
 	}
+	
+	static size_t min(size_t a, size_t b) {
+		return (a < b) ? a : b;
+	}