Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Pololu RC Switch User’s Guide 1. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1. Contacting Pololu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. RC Switch with Digital Output . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1. Components of the RC Switch with Digital Output . . . . . . . . . . . . 2.2. Connecting the RC Switch with Digital Output . . . . . . . . . . . . . . 2.3.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 1. Overview The Pololu RC switches allow you to turn devices on and off using standard radio control (RC) pulses. These switches can be used with standard hobby RC systems for radio-controlled switch applications. Example applications include using extra channels on an RC receiver or servo controller to turn on lights, motors, or irrigation valves.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation The Pololu 4-Channel RC Servo Multiplexer [https://www.pololu.com/product/2806] is an RC switch with an integrated quad 2-input multiplexer and a voltage regulator. It allows easy switching of servo control between two independent sources. It is ideal for applications in which you have two possible control sources and want to be able to switch between them on the fly. The RC multiplexer is available fully assembled [https://www.pololu.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 2. RC Switch with Digital Output 2.1. Components of the RC Switch with Digital Output Pololu RC Switch with Digital Output, labeled top view. The Pololu RC Switch with Digital Output has 7 through holes spaced 0.1″ apart that fit 0.1″ header pins. RC interface The GND, VRC, and RC IN pins make up the switch’s RC interface and can be connected directly to an RC receiver or servo controller: • The GND pin is the ground or reference voltage.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation When these outputs are high they will be at the same voltage level as VCC. When low, these outputs will be at 0 V (ground). These outputs do not have resistors in series with them. Each output can source or sink up to 25 mA. Configuration interface The learning mode jumper on the top of the board can be used to get the device into learning mode and configure it. The configuration procedure is described in Section 9.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Typical wiring diagram for the Pololu RC Switch with Digital Output. The RC switch can be plugged directly into an RC receiver or servo controller using a Female-Female servo extension cable. These can be found in our Servo Cables [https://www.pololu.com/category/112/servo-cables] category.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation This schematic is also available as a printable pdf [https://www.pololu.com/file/download/pololu-rc-switchwith-digital-output-schematic-diagram.PDF?file_id=0J700] (126k PDF). 2.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 3. RC Switch with Small Low-Side MOSFET 3.1. Components of the RC Switch with Small Low-Side MOSFET Pololu RC Switch with Small Low-Side MOSFET, top labeled view. The Pololu RC Switch with Small Low-Side MOSFET has 11 through holes spaced 0.1″ apart that fit 0.1″ header pins.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation The bottom of the board has jumpers that can be bridged with solder in order connect VCC to VRC or VCC to LOAD HIGH. These jumpers provide extra flexibility in how the system is powered, and some examples are given in Section 3.2. Load interface The LOAD LOW and LOAD HIGH pins are connections for your load and load supply.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Pololu RC Switch with Small Low-Side MOSFET with included hardware. 3.2. Connecting the RC Switch with Small Low-Side MOSFET The typical way to connect the Pololu RC Switch with Small Low-Side MOSFET is shown in the diagram below: Pololu RC Switch with Small Low-Side MOSFET, typical wiring diagram. The RC switch can be plugged directly into an RC receiver or servo controller using a Female-Female servo extension cable.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Power for the board’s logic needs to be applied to GND and VCC and must be between 2.5 V and 5.5 V. A 5 V regulator would be a good choice for the logic power supply. A 3-cell NiMH battery pack [https://www.pololu.com/category/104/3.6-v-nimh-battery-packs] would also work, but a 4-cell NiMH battery pack can be well over 5.5 V when fully charged and would not be suitable.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Large or capacitive loads can cause problems if the same supply is used for the logic (VCC) and the load. In such a configuration, when the MOSFET turns on, VCC might drop below 2.5 V, causing the board to reset. If you try to activate the switch but the board just goes into safe-start mode instead, you might have a power issue, especially if the problem only happens when the load is connected.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 4. RC Switch with Medium Low-Side MOSFET 4.1. Components of the RC Switch with Medium Low-Side MOSFET Pololu RC Switch with Medium Low-Side MOSFET, labeled top view. The Pololu RC Switch with Medium Low-Side MOSFET has 12 smaller through holes spaced 0.1″ apart that fit 0.1″ header pins and four larger holes that fit 3.5 mm screw terminals.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Outputs and indicator LED The RC switch provides feedback about what state it is in via a yellow indicator LED. The LED behavior is described in Section 8. Status information is also provided by two additional outputs: • The GOOD pin indicates the presence of a valid RC signal (10–330 Hz pulse rate, 0.5–2.5 ms pulse width). • The OUT pin indicates whether the MOSFET is on.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Pololu RC Switch with Medium Low-Side MOSFET with included hardware. 4.2. Connecting the RC Switch with Medium Low-Side MOSFET The typical way to connect the Pololu RC Switch with Medium Low-Side MOSFET is shown in the diagram below: 4.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Typical wiring diagram for the Pololu RC Switch with Medium Low-Side MOSFET. An onboard regulator allows the switch to be powered from voltages between 2.5 V and 16 V. However, for most applications we recommend using a 4- or 5-cell NiMH or NiCD battery pack to power the switch. The battery pack will typically be connected to an RC receiver or servo controller [https://www.pololu.
Pololu RC Switch User’s Guide Pololu RC Switch with Medium LowSide MOSFET with included terminal blocks and headers soldered to the component side. © 2001–2015 Pololu Corporation Pololu RC Switch with Medium LowSide MOSFET on a breadboard. 4.3. Schematic Diagram for the RC Switch with Medium Low-Side MOSFET The schematic diagram of the Pololu RC Switch with Medium Low-Side MOSFET is shown below: This schematic is also available as a printable pdf [https://www.pololu.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 5. RC Switch with Relay 5.1. Components of the RC Switch with Relay Pololu RC Switch with Relay, labeled top view. The Pololu RC Switch with Relay has five pins spaced 0.1″ apart that give access to its logic interface. RC interface The GND, VRC, and RC IN pins make up the switch’s RC interface and can be connected directly to an RC receiver or servo controller: • The GND pin is the ground or reference voltage.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation These pins are electrically isolated from the logic side of the board and are routed on the PCB with a minimum clearance of 60 mils (1.5 mm) from other copper and from the board edges, though manufacturing variations in the board edges can make those distances slightly lower. In most applications, the current and voltage ratings for the module will match the ratings of the relay used.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Pololu RC Switch with Relay, bottom view with dimensions. Included hardware The Pololu RC Switch with Relay is available in two versions: • The assembled version [https://www.pololu.com/product/2804] ships with the 5V Omron relay, header pins, and terminal block soldered in. A 1×2-pin male header and a shorting block are also included with the assembled version and can be used together as a tool when configuring the device.
Pololu RC Switch User’s Guide Pololu RC Switch with Relay (Assembled) with included hardware. © 2001–2015 Pololu Corporation Pololu RC Switch with Relay (Partial Kit). 5.2. Connecting the RC Switch with Relay The typical way to connect the Pololu RC Switch with Relay is shown in the diagram below: Typical wiring diagram for the Pololu RC Switch with Relay. We generally recommend that you use a 4- or 5-cell NiMH or NiCD battery pack for the logic power supply.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation The Pololu RC Switch with Relay connected to a typical RC receiver. 5.3. Schematic Diagram for the RC Switch with Relay The schematic diagram of the Pololu RC Switch with Relay is shown below: 5.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation This schematic is also available as a printable pdf [https://www.pololu.com/file/download/pololu-rc-switchwith-relay-schematic-diagram.pdf?file_id=0J682] (165k pdf). 5.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 6. Pololu 4-Channel RC Servo Multiplexer 6.1. Components of the 4-Channel RC Servo Multiplexer Pololu 4-Channel RC Servo Multiplexer (Assembled), labeled pinout. RC interface The Pololu 4-Channel RC Servo Multiplexer has a total of 13 RC servo channels: • The four inputs M1–M4 are called the master inputs. • The four inputs S1–S4 are called the slave inputs. • The four outputs OUT1–OUT4 are the main outputs of the device.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Note that SEL is the only input that requires a valid RC servo signal (10–330 Hz pulse rate, 0.5–2.5 ms pulse width); the master and slave inputs can be general digital signals. For example, you could use OUT4 to control the brightness of a small (< 20 mA) LED by sending PWM signals to the inputs on S4 and M4. Power The power supplied by the master RC device should be between 2.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Pololu 4-Channel RC Servo Multiplexer, bottom view with dimensions. Included hardware The Pololu 4-Channel RC Servo Multiplexer is available in two versions: • The assembled version [https://www.pololu.com/product/2806] ships with the headers pins soldered in to every through-hole except the extra slave power connection pins, as shown in the left picture below. A shorting block is included for optional use with the FAILMODE jumper pins.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation We recommend that you connect the SEL and M1–M4 inputs to a single “master” RC device, such as an RC receiver or servo controller. The master device should have a power source that supplies power the RC multiplexer. The power supplied by the master should be between 2.5 and 16 V and it must be capable of supplying the current that the servos connected to the outputs draw.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 7. Functional Description This section documents the functions and behavior of the RC switch. The information in this section is not needed to use the device, but it might be helpful if you are curious about the details. Timing accuracy The timing accuracy of the RC switch is limited by its internal clock, which has an accuracy of ±2%. Because of this, the threshold and other timing parameters might vary by a few percent.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Even with the safe-start feature, unexpected activation of the switch is still possible. With the Pololu RC Switch with Relay, one way this could happen is if the switch is activated but the logic power supply is at 3 V, which is too low to actually turn on the relay. If the logic power rises from 3 V to 5 V then the relay could turn on unexpectedly. 7.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 8. Outputs and Indicator LED The OUT pin is an output that indicates whether the switch is active. The OUT pin is high whenever the integrated MOSFET or relay is turned on. The Pololu 4-Channel RC Multiplexer does not have an OUT pin, but the same signal could be accessed by soldering a wire to the board as described in Section 6.1. The GOOD pin is an output that indicates whether the signal is valid (10–330 Hz pulse rate, 0.5–2.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 9. Configuring Your RC Switch The RC switch has two user-settable configuration parameters, threshold and inversion, which are described in Section 7. This section and the following sections explain how to set both parameters. To configure the device, you will need to be able to connect and disconnect the two parts of the learning mode jumper. This will be required at several points by the instructions in the following sections.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation Pololu RC Switch with Medium Low-Side MOSFET, labeled top view. For the Pololu RC Switch with Medium Low-Side MOSFET, the learning mode jumper consists of a pair of exposed pads on the component side of the board. An alternate learning mode jumper is available on the other side of the board and is labeled “LRN”; you can use whichever jumper is more convenient.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation To make the contact, stick the two exposed pins into the two holes of the learning mode jumper and then tilt the tool towards the side and press on it to ensure a good connection with the inside edge of each hole. It is not sufficient to just rest the tool on the learning mode jumper; you must tilt it and apply some force. Pololu 4-Channel RC Servo Multiplexer (Assembled), labeled pinout.
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation ◦ If you want to use a custom threshold, you should send RC pulses to the device. The device will indicate that it recognizes the RC input signal by blinking the LED with a special pattern that consists of a fade in followed by a blink, with a period of 2 s. The device will calculate the minimum and maximum pulse widths seen during this phase of learning mode, and set the threshold equal to the point midway between them (the average).
Pololu RC Switch User’s Guide © 2001–2015 Pololu Corporation 3. Tap the learning mode jumper (connect it and then disconnect it). The indicator LED should be blinking with a 50% duty cycle and a period of 0.5 to indicate that there is no signal being received. If you see it doing a pattern where it fades in and then blinks, then you are still sending pulses to the device. You should figure out how to stop sending pulses, and start over at step 1. 4. Tap the learning mode jumper again.
