4.3.3 Programmers built around a non-PIC MCU.4.3.2 Programmers without an internal PIC/MCU.3 Operating Systems, Kernels, Libraries.The long protruding lever of the voltage switch literally asks to be switched to 5V when the rig is connected to 3V3 micro and let the magic smoke escape free. At 23 September 2013, 13:50:38 user Giorgos Lazaridis wrote: [reply Giorgos And this makes things more interesting, doesn't it?.I have had something like this on my breadboard PSU and I killed quite a lot of devices stupid enough to get killed by humble 5V before I realized to shorten the lever to about 3mm, which proved to be enough to switch easily, but intentionaly only. Surely it does! :-) Nevertheless, this is based on my very own experience. At 23 September 2013, 13:58:58 user solipso wrote: [reply Lazaridis.It was safe enough, but then i saw my stock bin with these sweet slide switches. At 23 September 2013, 17:09:18 user Giorgos Lazaridis wrote: [reply Giorgos My original design involved a HDD jumper.I also like these switches very much, especially with multiple poles and with good contacts (surely not those eBay cheapies with 0.3 to 0.7 Ohm ON resistasnce). Your hack justifies this bad habit and makes us look a bit less silly, though. Nevertheless, the idea is great as we, lazy dogs, always like to power our PIC circuits directly from PICKIT - regardless the current needed. At 23 September 2013, 21:20:51 user solipso wrote: [reply Lazaridis.You might want to insure that the switch you use is a make before break, otherwise the voltage will spike as you switch from one voltage to another. At 24 September 2013, 19:11:30 user jdraughn wrote:.Idea is OK, but not necessarily quite discontinuing of Vcc from pickit3? But if you have questions please use the forum instead to post it. Click here to go to the next page >.īEFORE you post a comment:You are welcome to comment for corrections and suggestions on this page. Keep on reading to see how I soldered the parts together on the pre perforated PCB (click here)Ĭontinue reading. You can definitely use one 300 Ohms resistor instead. Well, i just found it easier to connect them on the pre-perforated PCB. One may ask "Why use two 150 Ohms resistors and not one 300 Ohms?".
#Pickit 3 tutorial series
In that case, the two 150 Ohms resistors are bypassed by the switch and are not connected in series with the 360 Ohms resistor. The total series resistor is then 150+150+360=660 Ohms. The two 150 Ohms resistors (R3,R4) are connected in series with the 360 Ohms resistor. Say that the switch is OPEN (as in the schematic). The switch SW1 is used to select between 3.3 and 5V output. After all, the output voltage will never exceed the 5V. If for example the input voltage is 9V instead of 24V:Īs you can see, there is absolutely no reason to us higher supply voltage than 9 Volts. To keep the power dissipation low, select a lower input voltage. I strongly suggest to use proper heatsink for power above 1.5 Watts. It may not sound much, but if the circuit runs for a long time, the temperature on the LM will increase significantly. The power dissipation on the LM317 depends on two factors: The voltage difference (Vout - Vin) and the current: But since we need to have 5V output, the input voltage must be at least 6.5V (there is typical 1.25 to 1.5 voltage drop across the adjustment resistors). The LM317 can regulate anything between 1.5 and 40Vdc. The input voltage must be DC from a power supply. If you plan to use a 12Vdc PSU for input, then a 16V input capacitor is enough, you don't need to select higher rating to keep the capacitor size down to minimum. But I'd rather suggest you select the proper capacitor as per your input supply voltage. Typically, a 60V or higher voltage rating is suitable for any input voltage rating. I've left the voltage range open on purpose. To select between 3.3V and 5V, a miniature slide switch is used (click to enlarge):įirst, the input capacitor. So simple: Based on the LM317, its just a constant voltage power supply. Only provide a limited amount of current, up to 30 mA, at VDD from 1.8-5V to aĬonsider this: A single LED may consume as much as 20mA.
#Pickit 3 tutorial Pc
When using the USB connection, PICkit 3 can be powered from the PC but it can According to the PICkit™ 3 Programmer/Debugger User’s Guide: There is also another very important reason: To increase the current supply capability. Actually, i fried the PICkit3 PSU myself and i know for sure that it may happen. There are basically two reasons to build this circuit: First of all, it may happen - The internal PSU may be destroyed.
#Pickit 3 tutorial software
Why use such a circuit since the PICkit 3 has a built-in power supply software controlled.
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