This post is a quick summary of a Picaxe Solar Tracker Project that I have been working on for a long time. The reason you may be interested in this is because I am using a PICAXE-20X2 to both receive the GPS signal and calculate the Sun's position (Azimuth & Elevation) using the acquired data.
The GPS module is the EM-411, which outputs standard NMEA data sentences. This data needs to be parsed to extract the position, time of day and date. I found alot of good information on the WWW about how to do that, including on this forum. I wrote a detailed summary of the electrical connections and provide the short Picaxe BASIC code here:
http://www.mtmscientific.com/gps.html
Using the GPS data to calculate the Sun's position was alot harder! I found a program to do the calculation in standard BASIC and then had to modify it to work with Picaxe BASIC. The main challenge was doing all the math with unsigned 2 byte integers. Also, the trigonometric calculations of Sine, Cosine and Tangent were challenging in the sense that the accuracy was important. Calculation of the Equation of Time (EOT) was also challenging. Here is a link to the page that describes this part of the project and includes the Picaxe BASIC code:
http://www.mtmscientific.com/gps_2.html
I am working on a 3rd webpage that describes how to use a MEMS Acceleration sensor to move to the correct aiming direction with a Tilt-Tilt style tracker platform. I am hoping the forum finds this information interesting and useful.
Michael
The GPS module is the EM-411, which outputs standard NMEA data sentences. This data needs to be parsed to extract the position, time of day and date. I found alot of good information on the WWW about how to do that, including on this forum. I wrote a detailed summary of the electrical connections and provide the short Picaxe BASIC code here:
http://www.mtmscientific.com/gps.html
Using the GPS data to calculate the Sun's position was alot harder! I found a program to do the calculation in standard BASIC and then had to modify it to work with Picaxe BASIC. The main challenge was doing all the math with unsigned 2 byte integers. Also, the trigonometric calculations of Sine, Cosine and Tangent were challenging in the sense that the accuracy was important. Calculation of the Equation of Time (EOT) was also challenging. Here is a link to the page that describes this part of the project and includes the Picaxe BASIC code:
http://www.mtmscientific.com/gps_2.html
I am working on a 3rd webpage that describes how to use a MEMS Acceleration sensor to move to the correct aiming direction with a Tilt-Tilt style tracker platform. I am hoping the forum finds this information interesting and useful.
Michael