If you decide to engage in aircraft modeling and subsequently make a radio transmitter for your aircraft with your own hands, be prepared for the fact that this is a very difficult and costly business. In addition, there will always be a risk of operating on a frequency already in use.
Instructions
Step 1
Fix the resistors R3-R7 in the control panel and bring the axes of these resistors away from the control sticks. Resistors can be of almost any value. It is desirable, of course, to adhere to the range of 1-47 KΩ, but if it is not possible to do this, you can use up to 100 KΩ. In addition, it is not at all necessary to select the same resistors. Please note that there must be a resistor R3 on the throttle control channel so that the receiver, in the event of a loss of communication with the transmitter, can immediately set the value of this channel to "0", and send the rest to the neutral position.
Step 2
Reinforce on board:
- DA1 power stabilizer (with a voltage of 3.3 V for the entire device). Maximum current strength - 130 mA;
- microprocessor DD1;
- radio module for radio communication (for example, RFM42S1-433).
Step 3
The registers of the radio module can be roughly divided into the following groups:
- by general parameters (for assigning I / O, enabling the necessary interrupts, disabling unused internal peripheral modules, etc.). Usually these parameters are not changed during assembly.
- by the parameters of the radio path (i.e., frequency deviation, IF receiver bandwidth, data transmission rate, etc.). Calculate these parameters in MS Excel;
- on data transmission control (number of bytes ID, size of data packet, etc.);
- by setting the operating frequency. So the already mentioned RFM42S1-433 module will allow the use of frequencies 430-460 MHz.
Remember: it is undesirable to use the frequencies 433800-434000 MHz, since these frequencies are used for the operation of car alarms.
Step 4
Use VD1 LED for battery indicator. By the way, in this case, the resistor R8 will act as a current limiter through the LED and therefore it can be selected in the range from 240 to 510 Ohm (the lower the value, the brighter the indicator will light up).
Step 5
If you have a factory control panel with a "trainer connector", use the elements R9-R10 Kom, R10-47 KOhm, VT1-BC847, C10-100 PF together with it. Please note: almost any low-power transistor is suitable as VT1.
