| 1 | /** |
| 2 | * See documentation at https://nRF24.github.io/RF24 |
| 3 | * See License information at root directory of this library |
| 4 | * written by tong67 (https://github.com/tong67) |
| 5 | * edited by 2bndy5 (http://github.com/2bndy5) for compatibility with SpenceKonde's ATTinyCore |
| 6 | */ |
| 7 | |
| 8 | /* |
| 9 | * This sketch can determine the best settle time values to use for |
| 10 | * macros, defined as RF24_CSN_SETTLE_HIGH_DELAY and RF24_CSN_SETTLE_LOW_DELAY, |
| 11 | * in RF24::csn(). |
| 12 | * The settle time values used here are 100/20. However, these values depend |
| 13 | * on the actual used RC combination and voltage drop by LED. The |
| 14 | * intermediate results are written to TX (PB3, pin 2 -- using Serial). |
| 15 | * |
| 16 | * For schematic details, see introductory comment block in the |
| 17 | * examples/rf24_ATTiny/rf24ping85/rf24ping85.ino sketch. |
| 18 | */ |
| 19 | |
| 20 | #include <stdio.h> |
| 21 | #include <SPI.h> |
| 22 | #include <Arduino.h> |
| 23 | #include <nRF24L01.h> |
| 24 | |
| 25 | |
| 26 | #if defined(ARDUINO) && !defined(__arm__) |
| 27 | #if defined(__AVR_ATtinyX5__) || defined(__AVR_ATtinyX4__) |
| 28 | #define RF24_TINY |
| 29 | #endif |
| 30 | #endif |
| 31 | |
| 32 | /****************************************************************************/ |
| 33 | |
| 34 | #if defined(RF24_TINY) |
| 35 | |
| 36 | // when Attiny84 or Attiny85 is detected |
| 37 | #define CE_PIN 3 /** "Chip Enable" pin, activates the RX or TX role */ |
| 38 | #define CSN_PIN 3 /** SPI Chip Select Not */ |
| 39 | |
| 40 | #else |
| 41 | // when not running on an ATTiny84 or ATTiny85 |
| 42 | #define CE_PIN 7 /** "Chip Enable" pin, activates the RX or TX role */ |
| 43 | #define CSN_PIN 8 /** SPI Chip Select Not */ |
| 44 | |
| 45 | #endif |
| 46 | |
| 47 | #define MAX_HIGH 100 |
| 48 | #define MAX_LOW 100 |
| 49 | #define MINIMAL 8 |
| 50 | |
| 51 | // Use these adjustable variables to test for best configuration to be used on |
| 52 | // the ATTiny chips. These variables are defined as macros in the library's |
| 53 | // RF24/utility/ATTiny/RF24_arch_config.h file. To change them, simply define |
| 54 | // the corresponding macro(s) before #include <RF24> in your sketch. |
| 55 | uint8_t csnHighSettle = MAX_HIGH; // defined as RF24_CSN_SETTLE_HIGH_DELAY |
| 56 | uint8_t csnLowSettle = MAX_LOW; // defined as RF24_CSN_SETTLE_LOW_DELAY |
| 57 | |
| 58 | /****************************************************************************/ |
| 59 | void ce(bool level) { |
| 60 | if (CE_PIN != CSN_PIN) digitalWrite(CE_PIN, level); |
| 61 | } |
| 62 | |
| 63 | /****************************************************************************/ |
| 64 | void csn(bool mode) { |
| 65 | if (CE_PIN != CSN_PIN) { |
| 66 | digitalWrite(CSN_PIN, mode); |
| 67 | } else { |
| 68 | // digitalWrite(SCK, mode); |
| 69 | if (mode == HIGH) { |
| 70 | PORTB |= (1 << PINB2); // SCK->CSN HIGH |
| 71 | delayMicroseconds(csnHighSettle); // allow csn to settle |
| 72 | } else { |
| 73 | PORTB &= ~(1 << PINB2); // SCK->CSN LOW |
| 74 | delayMicroseconds(csnLowSettle); // allow csn to settle |
| 75 | } |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | /****************************************************************************/ |
| 80 | uint8_t read_register(uint8_t reg) { |
| 81 | csn(LOW); |
| 82 | SPI.transfer(reg); |
| 83 | uint8_t result = SPI.transfer(0xff); |
| 84 | csn(HIGH); |
| 85 | return result; |
| 86 | } |
| 87 | |
| 88 | /****************************************************************************/ |
| 89 | void write_register(uint8_t reg, uint8_t value) { |
| 90 | csn(LOW); |
| 91 | SPI.transfer(W_REGISTER | reg); |
| 92 | SPI.transfer(value); |
| 93 | csn(HIGH); |
| 94 | } |
| 95 | |
| 96 | /****************************************************************************/ |
| 97 | void setup(void) { |
| 98 | |
| 99 | #ifndef __AVR_ATtinyX313__ |
| 100 | // not enough memory on ATTiny4313 or ATTint2313(a) to use Serial I/O for this sketch |
| 101 | |
| 102 | // start serial port and SPI |
| 103 | Serial.begin(115200); |
| 104 | SPI.begin(); |
| 105 | // configure CE and CSN as output when used |
| 106 | pinMode(CE_PIN, OUTPUT); |
| 107 | if (CSN_PIN != CE_PIN) |
| 108 | pinMode(CSN_PIN, OUTPUT); |
| 109 | |
| 110 | // csn is used in SPI transfers. Set to LOW at start and HIGH after transfer. Set to HIGH to reflect no transfer active |
| 111 | // SPI command are accepted in Power Down state. |
| 112 | // CE pin represent PRX (LOW) or PTX (HIGH) mode apart from register settings. Start in PRX mode. |
| 113 | ce(LOW); |
| 114 | csn(HIGH); |
| 115 | |
| 116 | // nRF24L01 goes from to Power Down state 100ms after Power on Reset ( Vdd > 1.9V) or when PWR_UP is 0 in config register |
| 117 | // Goto Power Down state (Powerup or force) and set in transmit mode |
| 118 | write_register(NRF_CONFIG, read_register(NRF_CONFIG) & ~_BV(PWR_UP) & ~_BV(PRIM_RX)); |
| 119 | delay(100); |
| 120 | |
| 121 | // Goto Standby-I |
| 122 | // Technically we require 4.5ms Tpd2stby+ 14us as a worst case. We'll just call it 5ms for good measure. |
| 123 | // WARNING: Delay is based on P-variant whereby non-P *may* require different timing. |
| 124 | write_register(NRF_CONFIG, read_register(NRF_CONFIG) | _BV(PWR_UP)); |
| 125 | delay(5); |
| 126 | |
| 127 | // Goto Standby-II |
| 128 | ce(HIGH); |
| 129 | Serial.print("Scanning for optimal setting time for csn"); |
| 130 | |
| 131 | |
| 132 | /************************** Main program *********************************/ |
| 133 | |
| 134 | uint8_t result; // used to compare read/write results with read/write cmds |
| 135 | bool success = true; |
| 136 | uint8_t bottom_success; |
| 137 | bool bottom_found; |
| 138 | uint8_t value[] = { 5, 10 }; |
| 139 | uint8_t limit[] = { MAX_HIGH, MAX_LOW }; |
| 140 | uint8_t advice[] = { MAX_HIGH, MAX_LOW }; |
| 141 | |
| 142 | // check max values give correct behavior |
| 143 | for (uint8_t k = 0; k < 2; k++) { |
| 144 | bottom_found = false; |
| 145 | bottom_success = 0; |
| 146 | while (bottom_success < 255) { |
| 147 | csnHighSettle = limit[0]; |
| 148 | csnLowSettle = limit[1]; |
| 149 | // check current values |
| 150 | uint8_t i = 0; |
| 151 | while (i < 255 && success) { |
| 152 | for (uint8_t j = 0; j < 2; j++) { |
| 153 | write_register(EN_AA, value[j]); |
| 154 | result = read_register(EN_AA); |
| 155 | if (value[j] != result) { |
| 156 | success = false; |
| 157 | } |
| 158 | } |
| 159 | i++; |
| 160 | } |
| 161 | // process result of current values |
| 162 | if (!success) { |
| 163 | Serial.print("Settle Not OK. csnHigh="); |
| 164 | Serial.print(limit[0], DEC); |
| 165 | Serial.print(" csnLow="); |
| 166 | Serial.println(limit[1], DEC); |
| 167 | limit[k]++; |
| 168 | bottom_found = true; |
| 169 | bottom_success = 0; |
| 170 | success = true; |
| 171 | } else { |
| 172 | Serial.print("Settle OK. csnHigh="); |
| 173 | Serial.print(limit[0], DEC); |
| 174 | Serial.print(" csnLow="); |
| 175 | Serial.println(limit[1], DEC); |
| 176 | if (!bottom_found) { |
| 177 | limit[k]--; |
| 178 | if (limit[k] == MINIMAL) { |
| 179 | bottom_found = true; |
| 180 | bottom_success = 0; |
| 181 | success = true; |
| 182 | } |
| 183 | } else { |
| 184 | bottom_success++; |
| 185 | } |
| 186 | } |
| 187 | } // while (bottom_success < 255) |
| 188 | Serial.print("Settle value found for "); |
| 189 | if (k == 0) { |
| 190 | Serial.print("csnHigh: "); |
| 191 | } else { |
| 192 | Serial.print("csnLow: "); |
| 193 | } |
| 194 | Serial.println(limit[k], DEC); |
| 195 | advice[k] = limit[k] + (limit[k] / 10); |
| 196 | limit[k] = 100; |
| 197 | } // for (uint8_t k = 0; k < 2; k++) |
| 198 | Serial.print("Advised Settle times are: csnHigh="); |
| 199 | Serial.print(advice[0], DEC); |
| 200 | Serial.print(" csnLow="); |
| 201 | Serial.println(advice[1], DEC); |
| 202 | |
| 203 | #endif // not defined __AVR_ATtinyX313__ |
| 204 | } |
| 205 | |
| 206 | |
| 207 | void loop(void) {} // this program runs only once, thus it resides in setup() |