Earlier this week, fellow Hack a Day-er [Mike Nathan] reviewed Adafruit’s new iPhone/iPad app Circuit Playground. The comments on [Mike]‘s review turned to suggesting ElectroDroid as an alternative to Circuit Playground. Surprisingly, Hack a Day authors actually pay attention to the comments, so I’ve decided to throw my hat into the ring and offer up my review of ElectroDroid. For purposes of full disclosure, I have to add that I paid the $2.59 donation for a copy of ElectroDroid without ads, and have had no contact with the developers.
From the opening screen, I was presented with three tabs labeled “Calculators,” “Pin-out,” and “Resources” with a nearly innumerable amount of options beneath each tab. Compared with Circuit Playground, there are far too many options available to fully review in the short format of a blog post. I’ll try to hit the highlights as I go through each tab.
Of course ElectroDroid allows you to calculate the value of resistors from the color code and back again, and will give you a resistor value from an SMD resistor code. Interestingly, I couldn’t find a calculator to go from a resistor value to an SMD resistor code. While there is a table in the app to allow a value to SMD code conversion, I’d like to see that implemented as something a little more interactive.
Other calculators include inductor color codes, Ohm’s law, filters, voltage dividers, and everything else listed on the ElectroDroid website. As for the series/parallel resistor calculator, ElectroDroid differs somewhat from what [Mike] saw with Circuit Playground. Like every resistor calculator ever, you’re able to enter a desired value and have ElectroDroid pick out two resistors in the E6 through E192 series that when soldered together will match the desired value. Also, you can enter the value of two resistors and get the resulting parallel or serial value.
Unlike Circuit Playground which allows 9 resistors to be placed in either a serial or parallel setup, ElectroDroid limits the user to two. I’m thinking ElectroDroid is a little more representative of reality (why, exactly, would you ever have nine resistors wired in parallel beyond Physics 102 homework?), but the option to calculate the value of more than two resistors would be nice.
The second tab on ElectroDroid goes to a list of pinouts for all the common connectors one would expect to see on a daily basis. All the regulars are there – USB, serial (both DE9 and DB25 – a nice touch), parallel port, Ethernet, and every video connector I’ve ever seen. There are also some uncommon but vitally important diagrams for 25-pair phone cable and OBD-II automotive diagnostic system.
This is a tough category to review. It’s easy to complain that there are no pin-outs for Super Nintendo controllers, or the ADB or 25-pin SCSI ports found on my old Macs. For me to deduct points for not including extremely esoteric connectors would be wrong; ElectroDroid does a very good job of including pin-outs 99% of makers or builders would need. Here, ElectroDroid serves its purpose.
Under the resources tab, I was greeted with a 19-item list of stuff I should have already memorized. The connections for PIC and AVR programmers are featured in the first position, followed by tables of standard resistors, capacitors, schematic symbols, switch diagrams (SPST, DPDT, etc), Boolean logic symbols, and a very nice reference image for 78xx voltage regulator pin-outs.
The Resources tab includes a link to ChipDB, a website I have admittedly never heard about. This is a welcome feature for anyone who is looking for the pin-outs for the entire 40xx and 74xx logic family, but ChipDB only includes 311 entries in its database as of this writing. I can’t fault the ElectroDroid developer for the incompleteness of this database (it’s not even his), but I’d like to see more entries under this link.
When reviewing an app, or any reference work for that matter, there needs to be a distinction between what it is and what it can be. ElectroDroid is a fabulous tool and reference app that would be very much appreciated by 99% of the people sending projects into Hack a Day. If I judge ElectroDroid on what it can be, I’m left a little bit empty.
Like Adafruit’s Circuit Playground, I’d love to see the ability to take a picture of a resistor and have the app display the value. A ‘killer app’ for electronic reference tools would be a front end for alldatasheet.com that includes the ability to search, save, and display the datasheet for any imaginable component.
These are all nit-picking, pie-in-the-sky ideas, though, that don’t affect my impression of the app at all. ElectroDroid is more than worth the $2.59 price tag; while it may not be extremely useful for the analog gurus or those who can build computers out of bailing wire, it’s far more than sufficient for a tinkerer or maker who needs the occasional reference tool.
Addendum: Because getting screen shots off of an Android device is insane, I’d also like to add a recommendation for MyPhoneExplorer. It works.