So far, the sample files are not upgraded to a new version.
Because I did not find a library that would meet my needs I developed the one I present here.
- Contains settings for use with nRF24L01+ (in version 0.0.3 not fully tested).
- Based on manuals: SE8R01 specification version 1.6 2014-03-05 and nRF24L01P Product Specification 1.0.
- Development focused on the high level interface.
- Methods for low-level access to the chip are reserved.
- Contains own SPI, adaptable with suppressed connections for use in ATtiny85.
- Methods developed in order to use the automatism already contained in the chip.
- Development for the purpose of chip compatibility.
- It enables up to 254 radios.
The compilation is active for the SE8R01 chip with the __SE8R01__ directive.
In case of compiling to nRF24L01+, use the __nRF24L01P__ directive.
For convenience, the possibility of including the directives in the main file before the declaration #include <acRF24.h> was implemented,
or
go to the top of the file acRF24directives.h and change the comment as desired.
#if !defined(__SE8R01__) && !defined(__nRF24L01P__)
/************************************************************/
/* Comment out the unused directive. */
/* */
#define __SE8R01__ // <- Comment if you do not use
// #define __nRF24L01P__ // <- Comment if you do not use
/* */
/************************************************************/
#endif
Fan-Out Mode uses the first byte of payload to identify the radio from which
the message is being sent. Therefore the maximum data size becomes 31. The
process is internal and it is possible to have access to the information of
which radio is sending the message, when calling sourceID ().
This method facilitates the use of up to 254 radios:
– Radio ID 0 indicates no radio and will be ignored;
– Radio ID 255 indicates header, will be ignored.
Quantity: 256 - (neutral + header) = 254.
For many radios there is an expressive use of memory, for this reason a base
configuration of 24 radios has been chosen. If a larger number of radios are required, include the directives
#define RADIO_AMOUNT 24
with the desired value in the main file before the
#include <acRF24.h>
statement.
or
then change to acRF24directives.h:
#if !defined(RADIO_AMOUNT)
/************************************************************/
/* Number of radios (Change to desired quantity). */
/* */
#define RADIO_AMOUNT 24
/* */
/************************************************************/
#endif
Replace 12 with the desired amount. Observe the limit of 254.
When the radio receiver falls for a long period of time, ACK does not return causing the transmitter to become inoperative.
watchTX() sets the time in milliseconds that the transmitter will wait
for the ACK response, while waiting is called reuseTXpayload(), after
this time flushTX() is called and thus releasing the transmitter to
operate with others radios
Call enableFanOut(true) to enable the possibility of receiving the
identification of the radio that is sending the message. This activation
should be common to radios that will commence.
Core for ATtiny used in this development:
David A. Mellis
Installation URL:
'https://raw.githubusercontent.com/damellis/attiny/ide-1.6.x-boards-manager/package_damellis_attiny_index.json'
and
Spence Konde (aka Dr. Azzy)
Installation URL:
'http://drazzy.com/package_drazzy.com_index.json'
Choose the corresponding json file, copy the URL and include in:
Preferences ... -> Additional URLs for Card Management:
Notice: - Spence Konde is a more complete work. - David A. Mellis uses less resource.
#define T_PECSN2OFF 220 // Capacitance in pF, time in milliseconds.
// External resistance chosen : 2200Ω
// Capacitor chosen by default : 100nF
// 2.2kΩ x 0.0000001uF = 0.00022s -> 220us standby time.
Note:
- When changing the resistor value, set the value of the T_PECSN2OFF directive to "acRF24direcrives.h". Without this adjustment the system may not work, or operate with weakness.
- It is not foreseen to change the value of the capacitor, the adjustment is only given by the change of the resistor. If this value is changed, also consider the need to adjust T_PECSN2ON. Values less than 5 for T_PECSN2ON causes inconsistency or inoperability in the system. Please report the result.
- Resistor with very low value interferes with loading the source code.
- Value of 1kΩ was tested and worked well. However it is necessary to connect it only after loading the source code, in the sequence reset.
- Use Germanium diode that gives voltage drop of 0.2V. Silicon Diode the minimum voltage value is 0.6V being required for the 0.3V chip.
//
+----|<|----x--[2k2]--x----|<|---- 5V
| 1n60 | | LED
| | | (red)
| +---||---x | +-----+
+-\/-+ | | 100nF | |--- CE 3| R R |
RESET PB5 1|o |8 Vcc --|--|--------|---------x--- VCC 2| S F |
NC PB3 2| |7 PB2 --x--|--------|------------- SCK 5| E 2 |
NC PB4 3| |6 PB1 -----|--------|------------- MISO 6| 8 4 |
+- GND 4| |5 PB0 -----|--------|------------- MOSI 7| R L |
| +----+ | +------------- CSN 4| 0 0 |
+--------------------------x---------------------- GND 1| 1 1 |
+-----+
| Troubleshoot |
|---|
| A parasitic resistance between CSN and VCC was found on some SE8R01 chip, which is still not defined. In case of failure the value of 2k2 must be increased so that in parallel to the parasitic value it results in an approximate value of 2k2 (try 2k7 or 3k3). The parasite resistor has an estimated value of 20k. |
The library provides an automatic method to adjust the chip limit clock.
Development tests were done between an Arduino UNO and an ATTiny85.
Initially the examples will be based on this configuration.
For lack of elaboration of a help file, please analyze the sample files. Adapt the same to the project need.
Due to the limited time available for development, I present this project in the way that you see it. I'm sorry, but so far I've been able to develop.
My English is weak, to the extent possible, depending on available time, I will translate.
Comments and suggestions will help in improving the project. Welcome.
I thank God.