|
| 1 | +/* |
| 2 | + Simple Sketch for testing HardwareSerial with different CPU Frequencies |
| 3 | + Changing the CPU Frequency may affect peripherals and Wireless functionality |
| 4 | + In ESP32 Arduino, UART shall work correctly in order to let the user see DGB info |
| 5 | + and other application messages. |
| 6 | +
|
| 7 | + CPU Frequency is usually lowered in sleep modes |
| 8 | + and some other Low Power configurations |
| 9 | +
|
| 10 | +*/ |
| 11 | + |
| 12 | +int cpufreqs[6] = {240, 160, 80, 40, 20, 10}; |
| 13 | +#define NUM_CPU_FREQS (sizeof(cpufreqs) / sizeof(int)) |
| 14 | + |
| 15 | +void setup() { |
| 16 | + |
| 17 | + Serial.begin(115200); |
| 18 | + delay(1000); |
| 19 | + Serial.println("\n Starting...\n"); |
| 20 | + Serial.flush(); |
| 21 | + |
| 22 | + // initial information |
| 23 | + uint32_t Freq = getCpuFrequencyMhz(); |
| 24 | + Serial.print("CPU Freq = "); |
| 25 | + Serial.print(Freq); |
| 26 | + Serial.println(" MHz"); |
| 27 | + Freq = getXtalFrequencyMhz(); |
| 28 | + Serial.print("XTAL Freq = "); |
| 29 | + Serial.print(Freq); |
| 30 | + Serial.println(" MHz"); |
| 31 | + Freq = getApbFrequency(); |
| 32 | + Serial.print("APB Freq = "); |
| 33 | + Serial.print(Freq); |
| 34 | + Serial.println(" Hz"); |
| 35 | + delay(500); |
| 36 | + |
| 37 | + // ESP32-C3 and other RISC-V target may not support 240MHz |
| 38 | +#ifdef CONFIG_IDF_TARGET_ESP32C3 |
| 39 | + uint8_t firstFreq = 1; |
| 40 | +#else |
| 41 | + uint8_t firstFreq = 0; |
| 42 | +#endif |
| 43 | + |
| 44 | + // testing HardwareSerial for all possible CPU/APB Frequencies |
| 45 | + for (uint8_t i = firstFreq; i < NUM_CPU_FREQS; i++) { |
| 46 | + Serial.printf("\n------- Trying CPU Freq = %d ---------\n", cpufreqs[i]); |
| 47 | + Serial.flush(); // wait to empty the UART FIFO before changing the CPU Freq. |
| 48 | + setCpuFrequencyMhz(cpufreqs[i]); |
| 49 | + Serial.updateBaudRate(115200); |
| 50 | + |
| 51 | + Freq = getCpuFrequencyMhz(); |
| 52 | + Serial.print("CPU Freq = "); |
| 53 | + Serial.print(Freq); |
| 54 | + Serial.println(" MHz"); |
| 55 | + Freq = getXtalFrequencyMhz(); |
| 56 | + Serial.print("XTAL Freq = "); |
| 57 | + Serial.print(Freq); |
| 58 | + Serial.println(" MHz"); |
| 59 | + Freq = getApbFrequency(); |
| 60 | + Serial.print("APB Freq = "); |
| 61 | + Serial.print(Freq); |
| 62 | + Serial.println(" Hz"); |
| 63 | + if (i < NUM_CPU_FREQS - 1) { |
| 64 | + Serial.println("Moving to the next frequency after a pause of 2 seconds."); |
| 65 | + delay(2000); |
| 66 | + } |
| 67 | + } |
| 68 | + Serial.println("\n-------------------\n"); |
| 69 | + Serial.println("End of testing..."); |
| 70 | + Serial.println("\n-------------------\n"); |
| 71 | +} |
| 72 | + |
| 73 | +void loop() { |
| 74 | + // Nothing here so far |
| 75 | +} |
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