Discussion:

https://www.reddit.com/r/cycling/comments/4ufya2/advantages_of_dedicated_cycling_computer_instead/

https://www.reddit.com/r/cycling/comments/50m53j/cycle_computer/ --- discussion of cycling computer vs. smartphone

https://www.reddit.com/r/cycling/comments/4zumt3/whats_the_computer_for_turnbyturn_directions/

• Bryton Rider 310 *

• Cateye

• CatEye CC-RD300W Strada Wireless * **

• Cateye Stealth 50 *

• Cateye Velo7 (wired) *

• Giant

• Axact 6 Wired Computer

• Garmin *

• Garmin 25 *

• Garmin 510 *

• Garmin Edge 20 *

• Garmin Edge 25 * ** ***

• Garmin Edge 520 * ** *** **** ***** how to sideload OpenStreetMaps Detailed review *

• Garmin Edge 800 *

• Garmin Edge 810 * **

• Garmin Edge 820 *

• Garmin Touring * ** ***

• Raniaco Bike Computer *

• Sigma

• Sigma Sport ROX 5.0 Cyclocomputer, Black (Amazon) *

• Sigma Rox 5.0 --- I don't know of any $50 computers that do heart rate.*

• http://www.sigmasport.com/en/produkte/fahrrad-computer/topline-2012/wired/bc512 *

• Wahoo ELEMNT --- screen is able to be read in all light conditions, it is very customizable, works with Bluetooth and ANT+, and now does turn-by-turn GPS directions using RideWithGPS routes.*

• Elemnt Bolt * **

An alternative is a GPS:

• General-purpose or hiking *

• Wearable

• https://www.reddit.com/r/cycling/comments/4ukx28/what_wearable_gps_watch_do_you_suggest/

• http://spectrum.ieee.org/geek-life/hands-on/build-a-readable-bicycle-computer

• http://jeremyblythe.blogspot.co.uk/2013/02/live-web-bicycle-dashboard-using.html

• Garmin eTrex 20 *

Raspberry Pi

• https://www.johannesbader.ch/2014/06/track-your-heartrate-on-raspberry-pi-with-ant/ *