Translating an embedded C algorithm
in [ADA]
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From: Talulah on 15 Jan 2007 09:36 Hi, I am in the process of writing a book about real-time embedded development (hardware and software). In it there is a section on different programming languages that are available for embedded development. I'm using a small C function that does temperature measurement by linear interpolation of a lookup table as an example. I have C code to do this, and would like to have the same algorithm implemented in other languages. Unfortunately I'm really a C programmer, with very little experience of other languages, so I would like to ask if anyone on this newsgroup is interested in translating the algorithm into Ada. Of course you would be mentioned in thanks in the book once it is finished. If you are interested, I have placed the section of the book here: http://homepages.which.net/~paul.hills/Temporary/Temperature.pdf so you can see the code and description. Please email me if you are interested to paul (dot) hills (who is at) uk (dot) landisgyr (dot) com. Thanks very much Paul Hills
From: Jeffrey Carter on 15 Jan 2007 19:06 Talulah wrote: > > I am in the process of writing a book about real-time embedded > development (hardware and software). > > Unfortunately I'm really a C programmer, with very little experience > of other languages, ... I would think that someone qualified to write such a book would be familiar with at least one language that was designed for RT embedded SW development. Such a language would have things like tasking, timing, and fixed-point types built in. Clearly C is not such a language, so I have to wonder about the qualifications of someone who only knows C.
From: Marc A. Criley on 15 Jan 2007 20:10 On Tue, 16 Jan 2007 00:06:59 +0000, Jeffrey Carter wrote: > Talulah wrote: >> >> I am in the process of writing a book about real-time embedded >> development (hardware and software). > Clearly C is not such a language, so I have to wonder about the > qualifications of someone who only knows C. Thanks Jeff, go ad hominem on someone who's unfamiliar with Ada yet willing to give it a fair hearing. -- Marc A. Criley -- McKae Technologies -- www.mckae.com -- Avatox - DTraq - XIA - XML EZ Out
From: Cesar Rabak on 15 Jan 2007 21:21 Jeffrey Carter escreveu: > Talulah wrote: >> >> I am in the process of writing a book about real-time embedded >> development (hardware and software). >> Unfortunately I'm really a C programmer, with very little experience >> of other languages, ... > > I would think that someone qualified to write such a book would be > familiar with at least one language that was designed for RT embedded SW > development. Such a language would have things like tasking, timing, and > fixed-point types built in. Can you please enlight us why "Such a language *would have* things like" and not "programming in a such language that has things like..." > > Clearly C is not such a language, so I have to wonder about the > qualifications of someone who only knows C. And why cannot C be augmented by RTOSs and other systems software to achieve this? Instead of taking profit of an opportunity you rather just spit a bit of arrogance? How does this helps Ada?
From: Vo, Anh (US SSA) on 15 Jan 2007 22:50
-----Original Message----- From: comp.lang.ada-bounces(a)ada-france.org [mailto:comp.lang.ada-bounces(a)ada-france.org] On Behalf Of Talulah Sent: Monday, January 15, 2007 6:37 AM To: comp.lang.ada(a)ada-france.org Subject: Translating an embedded C algorithm << [..] Unfortunately I'm really a C programmer, with very little experience of other languages, so I would like to ask if anyone on this newsgroup is interested in translating the algorithm into Ada. Of course you would be mentioned in thanks in the book once it is finished. If you are interested, I have placed the section of the book here: http://homepages.which.net/~paul.hills/Temporary/Temperature.pdf so you can see the code and description. Please email me if you are interested to paul (dot) hills (who is at) uk (dot) landisgyr (dot) com. >>> Here I just translated directory to Ada from C code in the table. Please pay attention to the Important Note below the Table. Note also that I have slightly modified some variables for readability. Let me know if more information is desired. AV ------------------------------------------------------------------------ --| MeasureTemperature --| --| Calculates the temperature in ºC given the ADC count by lookup --| table and linear interpolation of the diode circuit characteristic. --| --| Parameters: --| AdcCount Raw ADC count. --| --| Returns: --| Temperature in ºC x 10. INVALID_TEMPERATURE if out of range. --| --| Note: GNAT-GPL-2006 compiler on Windows was used ------------------------------------------------------------------------- function Measure_Temperature (Adc_Count : in Integer) return Integer is Index : Integer := 0; InterpolationDistance : Integer := 0; TempDiff : Integer := 0; TempCalOffset : Integer := 0; Temperature : Integer := 0; TEMPERATURE_TABLE_NUM_ENTRIES : constant := 32; Table : constant array (0 .. TEMPERATURE_TABLE_NUM_ENTRIES - 1) of Integer := ( 1171, 1116, 1061, 1006, 952, 899, 846, 793, 741, 689, 638, 588, 537, 488, 438, 389, 341, 293, 246, 199, 152, 106, 61, 16, -29, -73, -116, -160, -202, -244, -286, -327); -- *** Important Note: -- The following constants and function need to be defined. -- They are arbitrary set so compilation is successful. MINIMUM_ADC_COUNT : constant := Integer'Last; MAXIMUM_ADC_COUNT : constant := Integer'Last; SPACING : constant := 1; TEMPERATURE_CAL_VALUE : constant := 0; function ReadEEPROM (Temp : in Integer) return Integer is begin return Temp; -- for now end ReadEEPROM; ----------------------------------------------------------- begin -- Index is the index into the table. Each table entry is 8 ADC -- counts higher than the last one, so subtract the offset and -- divide by 8 to find the table index. InterpolationDistance -- is the linear distance between the the table entry ADC cou nt -- and the actual ADC count. -- Check range of Adc_Count and saturate index if out of range. if (Adc_Count < MINIMUM_ADC_COUNT) then -- Underflow of ADC - saturate at minimum value Index := 0; elsif (Adc_Count > MAXIMUM_ADC_COUNT) then -- Overflow of ADC - saturate at maximum value Index := TEMPERATURE_TABLE_NUM_ENTRIES - 1; else -- Find the index of the table entry just below the ADC value Index := (Adc_Count - MINIMUM_ADC_COUNT) / SPACING; end if; -- Calculate the interpolation between the table entries either side of -- the ADC value. This is the remainder of the difference between the -- ADC count and the minimum temperature ADC count divided by the -- spacing between table entries. Since the spacing is a power of 2, -- this can be achieved by simply masking all but the bottom 3 bits. InterpolationDistance := (Adc_Count - MINIMUM_ADC_COUNT) + (SPACING - 1); TempDiff := (Table(Index) - Table (Index+1)); -- The temperature is then the base temperature minus the amount -- calculated by linear interpolation. The compiler is clever enough -- to know that dividing by 8 is a right shift of three bits. Temperature := Table(Index) - ((TempDiff * InterpolationDistance) / SPACING); -- To this is then added the calibration offset to the temperature table. TempCalOffset := ReadEeprom (TEMPERATURE_CAL_VALUE); Temperature := Temperature + TempCalOffset; return Temperature; end Measure_Temperature; |