[NRVR-Members] EggTimer Sale and NRVR Build Session

Jordan Truesdell jordan at truesdell.org
Sun Nov 25 21:01:54 CST 2018

I just wrote this up for an iPhone user. I meant to forward it to the group but...email is hard. 

The question was "what do I need to get this data onto my iPhone"

(1) All the GPS transmitters work with all the receivers he sells. 
(2) Apple and generic GPS data don't mix. 
      A  buy LCD receiver and manually type the coordinates into Maps,
      B  get Android, or 
      C  buy the "extra" GPS RX module and forget the phones altogether. 

Long version. (sit down, grab a beer)

Bluetooth GPS and iPhones don't play nice. More specifically, Apple doesn't support external serial data over bluetooth, so even if you find a module that will say the magic Apple words, there are no apps which can take that data and put it on a map. If you want a snazzy GPS+iPhone app, you'll have to spend $350 on a Featherweight GPS tracker. Or go find a $10 Android phone and dedicate it to rocket tracking. Kroger has LG tracphones on sale every few months. 

On to the product dump. BTW - I made this myself, so it's probably slightly wrong. But I think it's mostly right. 

There is one altimeter which includes GPS, which is the Eggtimer TRS GPS/Flight Computer ($70). The whole line goes like this:

Mini - GPS transmitter that fits in a 24mm body tube
TX GPS transmitter that fits in a 38mm body tube

GPS + Altimeter
TRS - a flight computer / altimeter which also has a GPS transmitter on it

Altimeter Only
Quark - 2 outputs at apogee and 500', barometric only, peak altitude beeps out at landing
Classic - flight altimeter that's easy to assembly (no surface mount); 2 channels, flight data recorder, USB interface with PC
Quantum - Classic, but with surface mount components and wifi programming (and possibly arming..I'm not sure)
Proton - flight altimeter with 6 channels, 120G accelerometer, wifi programming/arming

It doesn't matter which GPS you get, they all work with all of the GPS receivers.
  ***The GPS Receivers aren't used for setting the altimeter, they just receive data from the GPS***

The receiver for the GPS module breaks down into two options, each with a sub-variant, and these all get data from all of the GPS transmitters
(1a) Wireless receiver board + USB cable - you plug it into your PC and it sends GPS data to you just like you had a 1000' long serial cable plugged into your rocket
(1b) Wireless Receiver board + bluetooth module - you virtually plug the BT into your Android phone or PC and it sends GPS data to you just like you had a 1000' long serial cable plugged into your rocket

          You can upgrade from 1a to 1b at any time with a $7 HC06 Bluetooth board off Amazon and a 4 pin standard jumper cable. 

(2a) LCD display and small microprocessor with a wireless module all on one board. It displays the current GPS coordinates of your rocket, which you can type into your iPhone Maps application 
(2b)  LCD display and small microprocessor with a wireless module PLUS another GPS receiver module that plugs into it.  It displays the current GPS coordinates of your rocket, distance to your rocket, and an arrow pointing towards your rocket. No other device is required. 

         You can upgrade from 2a to 2b at any time with the $40 GPS ($34 on sale) module from EggTimer
         You can put a USB cable or a bluetooth module on the LCD version - it has the pin header for it - and get both the LCD readout and the link to your PC or Android phone at the same time. 
         You CANNOT upgrade from 1 to 2. You buy a new one and you now have a backup receiver. Or use a second receiver for staged flights with two transmitters (because we haven't spent enough money already, amirite?)

On 11/25/2018 7:16:46 PM, Jordan Truesdell <jordan at truesdell.org> wrote:
Hey everybody,

Egg Timer Rocketry is having a sale. It happens once a year and you can get their rocketry electronics (altimeters, wifi switches, deployment computers, GPS trackers etc.) for $5-20 off. The gear is generally very affordable, from $15 for a dual deployment altimeter to $70 for the cheapest GPS receiver/transmitter kit. The catch is that you have to build the electronics from a kit. You get a bag o' parts - everything you need from pcbs to solder to heat shrink - and a link to an assembly PDF with detailed instructions. You supply the soldering iron, some tape, and your time.  The simple kits take less than an hour to build, the more complex ones can take two hours.  

As challenging as they are to build alone, I think they'd be fun - and a lot less stressful - to build as a group. They're not difficult, per se, but there are some tricks to working with the small parts and assembly techniques. To that end, if anyone wants to try out a build-you-own avionics I'm going to host a build party for the Eggfinder(/timer) kits in mid-January. I'm thinking around the last week of January would be best.  If you get a kit, ping me off-list (jordan at truesdell.org). Presuming we have interest we'll set up a date and converge on a convenient location with soldering irons, magnifying glasses, and spare hands to put them all together and test them.  

On 11/25/2018 6:18:56 PM, Thomas Tweeks Weeks <tom at theweeks.org> wrote:
Got the links reversed.. :)
If you're not on fbook.. the sale info is here:
http://eggtimerrocketry.com/eggtimer-rocketry-holiday-sale/ [http://eggtimerrocketry.com/eggtimer-rocketry-holiday-sale/?fbclid=IwAR1CFBoxIUR5y--AxIHzOtsGrwtJoHNmB6ndxotdjdvxnA3u53GJ8X63eeI]
Cris (the owner) only does purchases via email + paypal.. So jump in now if you're thinking about doing so.
Stay tuned for a Q1 date or Jordan to post follow up details here.
Anything else Jordan?
On Sunday, November 25, 2018 5:03pm, "Thomas Tweeks Weeks" <tom at theweeks.org> said:

Hey all..
Jordan posted something on our fbook group about doing a group build of EggTimer trackers and flight computers:
http://eggtimerrocketry.com/eggtimer-rocketry-holiday-sale/ [http://eggtimerrocketry.com/eggtimer-rocketry-holiday-sale/?fbclid=IwAR1CFBoxIUR5y--AxIHzOtsGrwtJoHNmB6ndxotdjdvxnA3u53GJ8X63eeI]
If you're not on fbook, see here:
https://www.facebook.com/groups/NRV.Rocketry/permalink/2464862803540486/ [https://www.facebook.com/groups/NRV.Rocketry/permalink/2464862803540486/] 
Maybe Jordan can follow up on specifics (dates, etc) here and I can book us a room (probably some time in Jan/Feb).
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