The entire remote control is handled by a PIC that controls the GSM/GPRS module’s activity and gives commands to the two relays. Having said that, let’s take a better look at the electric scheme: power is supplied by continuous voltage, not always stabilized (applied to PWR + and -) at a value between 5 and…
The full GSM thermostat is managed by a Microchip PIC18F46K20-I/PT microcontroller, programmed with a firmware that controls the temperature and takes care of the communication with the GSM module which is the component named GSM; this is, in fact the small board hosting the cell, so the pins’ numbers refer to the used pin-strips’ contacts….
Excellent to remotely control via GSM the activation of engines, lightening or watering systems and alarm systems. It sends commands through SMS as well as with DTMF dual tones and allows you to check if they were successful. In this post we present the last application created from the development of the modular remote control…
For the GSM temperature controller we have provided a double-sided PCB with plated holes, made by photoengraving; once you have the board you can start the assembly with SMD components.
The thermal probe can also be mounted out of the PCB, connecting it somewhere else by means of a three-conductor cable, at least 20 meters long.
It allows you to remotely control up to two different electrically controlled units and to remotely read the condition of as many devices or the presence of tension on power lines. We describe the simple remote control, obtained by adding to the regular circuit, two optocouplers and both relays, together with the basic components. The…
Let’s now look into the schematic diagram; in it you can note the usual Microchip microcontroller governing the GSM/GPRS module activity, controlling the logical condition of the two opto-isolated inputs and managing the two relays. Moreover, the PIC interacts with the DTMF decoder in order to recognize the dual tones used for the phone selection…
In order to understand the different functions, let’s now take a look at the schematic diagram of the unit. 2 IN and 2 OUT Schematic Diagram The entire control is handled by a Microchip PIC18F46K20-I/PT microcontroller, programmed with a firmware that controls the GSM/GPRS module’s activity, reads the logic condition of the two opto-isolated inputs and sends…
On the construction perspective, the remote control does not present many difficulties, just the obvious ones that appear when working with circuits requiring superficial assembly components. As usual, there is a PCB with double plating where to mount all components.
Now that we have seen the electric scheme, we can work on the practical aspect of the project; let us state in advance that its making presupposes a double-faced printed board with metallic holes, using many SMD components, all this in order to reduce the overall size of the device.
The set of commands of this remote is divided into two categories: the SMS ones and the DTMF tones. The former are simply summarized in the corresponding table, since they are the same as the ones described for remote 2 IN/2 OUT. Here we will only describe in detail the DTMF commands, first stating that…
Commands can be given in two different ways: the first one is to send the SMS according to required syntax and with the password (if required), needful to avoid strangers to operate the configuration; the second one is to introduce, through Easy Setup, the number of the mobile enabled to make the following settings via…
Now you have to get to know the commands needed to manage it and use them at their best. Relevant commands must be given by SMS, on the understanding that a message can contain multiple messages properly separated; some commands, due to their importance, they require a password which is 12345, set by default during…
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